Improvised Handgun - some thoughts

[zaibatsu]

Recently I've been thinking about how to design a pistol so that it could be made with relatively simple tools but still be able to handle cartridges of moderate power (9mmP and higher). The problem with this is you need some way to decrease the speed with which the slide opens. The first way would be to increase the weight of the slide, but this would lead to a pistol that was far too heavy and there'd still be problems with extraction.

The other method would be something like the browning tilting barrel system. Firstly, I would modify the barrel to correspond with the design of a glock's - no link with a diagonal slot which could be driled out and dressed with a file. The part of the slide containing the firing pin etc could be machined from a block of steel and attached using appropriate methods. I think gas-delaying systems such as in the steyr pistol would be too difficult/require too much R&D to be feasible.

Then there is the problem of the construction of the slide. I think it would be a good idea to make this from stamped steel, as this would decreased the amount of time spent milling steel and also the cost of the handgun. I think it'd be possible to construct a hydraulic press with the potential to do some serious bending in a similar way to the construction of a hydraulic BP press.

Next, the locking lugs. These would require quite a bit of time and accuracy, so I think it would be best to use the same method as in the SIG P226 and use the ejection port of the pistol as the locking lug, with the breech block of the pistol protruding. I envisage the barrel being made from a cylindrical blank, and the end threaded to screw into a block which acts as the locking lug and the barrel dropping slot.

The frame could possibly be made from laminations of steel riveted/screwed together. This would remove the need for most internal milling. I would style the trigger mechanism after that of the "Tiny Tom" pocket pistol, as that seems to be very simple and as it is double-action only we could probably forget safeties. Magazine would be single stack to increase reliability and decrease the overall size of the handgun. Also a single stack mag is easier to make than a double stack.

This is just a brief idea of what I have been thinking of and I'd like to get feedback from other people on it. Remember we're not looking for ideals, we're looking for practical and "good enough" methods.

[guerrero]

Zaibatsu, reading your thougts about the problem with relatively high powerd cartridges in a improvised handgun I remembered the spanish Astra pistol of Worl War II. The problem is soluted with a relatively short barrel, a very strong spring and a relatively havy slide. It worked very well with different types of ammo (9mm largo, 9mm para, even 9mm short). Most parts are made with a turning-lathe. So I think this construction with some simplifications as hammerles construction in DAO like the german HK VP70 would be a very good one for home-production. What do you think about?

[Ammonal]

Could we try and limit the number of parts that require lathe and mill work? my reasoning for this is that these are two pieces of equipment which are a) highly useful and accurate for this kind of work, and b) expensive and hard to come by in some areas. Point a) is just acknowledging the quality of work that can be performed with such equipment but as we are looking to improvise this design which parts are an absolute must for milling and turning? As you have said the slide can be either be machined for a high quality and strength product, or press it from sheet metal. The breech is not particuarly hard to make if a drill press and a good assortment of files can be aquired. The barrels, providing that a chamber reamer is available can be reused from a number of rifles, one that comes to mind is my old 20" barrelled .357mag lever action; if you took the barrel from it you would have enough barrel for approx 6 handguns based on a 3" barrel. The barrel and the magazine would be the components which I would hold in highest priority to the overall design but then I would think all parts are important. Point b) is for if the user decides to outsource the machining, and the machinist doesnt like the look of what he has been asked to do then there could be some serious trouble with police, etc are brought in by the machinist.

Next as this is going to be improvised, would you seriously consider going right through and making this, I know SWIM would be interested in prototyping what he could, and I reckon it would be pretty damn nice if the forumites could come together and build, I mean propose a useful design that could have in some cases very good uses; because really single shot weapons just dont cut it when it comes to an enemy armed with automatic or semi automatic weapons.

[keith]

I have a design very similar to the grease gun of WWII. It would cost about $50 to build and would be fully automatic.
For your barrel you could simply use a peice of seamles high quality pipe for it. It would be smoothbore but with a 3" barrel, accuracy obviously isn't a consern. I havea .38 special/.357 mag. improvised handgun taht I made this year in my machining class. I'm lucky I ahev a nice shop teacher cause in my excitment of being finished I essembled it during class and everyone saw and knew what it was. I have a Mac not a windows computer so I dont know how I could shot you plans or pics but I'll try. My friend has a camera but I'll have to download teh softwere onto my computer. I'll try.

[jonesy]

First of all KEITH if u can send me the pics and info u have i will convert them to work on a PC, im sure the software is on my computer somewhere for that, if u can zipit up or what ever. Send me an email daleks_placebo@hotmail.com to discuss further. Id love to see what u have.
On the subject of Homemade pistols i think what we need to do is take the two ebooks 'Home wrkshop firams 2 pistol designs' and 'Expedient SMG' and read them through. As one book requires only home tools and the other a lathe andmilling machine.
I hear alot people mention about very simple and dangerous designs for firearms receivers, slides, triger assemblies etc but then rfer to it having a part or two that requires machining. To me this seems quit silly, as whty make a shity gun then risk being cought by out sourcing machining. Even know not many machine shaops would even know what a bold for a gun looks like especialy in australia.
This is why i have decided to theologicaly design a handgun bassed on the two books mention abouve. Yes one of the the books refers to a SMG but the basic principles remain the same.
One example being the lower receiver instead of making it from two peices of shaped steel weleded together, u could use sqare diameter steel tube of similal thickness, cut to the apropriate shape.
Refer to the books to see other items that can be substituted.
Personaly im finding the hardest part being the ejection of the cartrige and smooth loading of a new one.
thanks

--------------------
Don't use ghetto language!

Rhadon

[zaibatsu]

guerrero:

I don't think it is the ideal situation to use a heavier slide and increased strength spring. Straight blowback cartridges have problems with the extraction of higher pressure catridges, often requiring either case lubrication or a fluted chamber. With the design I suggest, .45ACP is possible, but I'm not sure it would work with the Astra design. I also think the Czech pistol "Little Tom" has the simplest trigger mechanism, I think trying to create a hammerless pistol will only add to the trouble of producing it and increase complexity. Unfortunately I can't find a cutaway on the internet to show you what I mean and my scanners fucked, although it is available in some books.

Ammonal:

I don't believe the barrel is the most important thing per se, reliability is more important that tack driving accuracy. Because of that I'd suggest the most important things are feeding and extraction. The pistol I'm thinking of could be made from scratch, including the barrel. I see no reason however for the barrel to be less well made than a commercial barrel. For prototyping it would be easier to use ready made barrels.

Unfortunately at the moment I have neither the capabilities nor the wish to actually produce this, although it would be very nice to produce a set of blueprints for the construction of the device, and see what others can do.

Keith:

I don't quite understand your description, it sounds like you are talking about some kind of machine pistol. That's not what I imagine building, as we'd be breaking no new ground

[Ammonal]

I know exactly what you mean zaibatsu, my importance in the barrel is mainly from experience with single shot weapons which you HAVE to rely on a degree of accuracy from your barrel (not that the barrel makes all the difference, it is more the hands of the user that create accuracy) because you only have one shot and that shot either has to buy you enough time to reload or get your victims weapon.

The thought of making a compact semi auto handgun is quite inspiring, I have dreamt of getting my hands onto something like the Smith & Wesson 2213, because it is small, in .22LR calibre which is ideal for my application and plentiful amounts of ammo, my only other option is to make something in .357mag, which is not something I am wishing to dive into without some experience with handguns and operation/mechanism/etc.

If we could develop a relatively small and compact handgun with single column magazine of 5-7 rounds, which was reliable and could be made from scratch with common and some machining (I believe for the reliability to be high that the feed/action/slide will more than likely be machined) and was capable to be manufactured by people who know what they are doing (ie not fools that cause accidents) Then the forums could really have something to show for those who whinge, complain 'my gun laws are too strict, etc, etc, etc' that you only have to use your head to get
from point A of being oppressed and unarmed to point B of being self reliant and defended.

I mean how many people would love to make one to just have to show off in your living room, and be able to say "I made that"; I know I sure as hell do!

[A-BOMB]

Well here is a simple pistol I just thought up for this post its made out of .75" steel tube to simplify construction the whole pistol is square steel tube. It only requires a drill, some taps, and some screws, and a file/hacksaw.

A: fireing pin striker
B: Boltface/weight
C: firing pin/return spring
D: recoil spring
E: barrel
F: trigger/sear/hammer/hammer spring

The other parts are self evident, this is just a diagram I leave finding the dementions to you.

ill add more of this in a minute but i got change batteries in this laptop, are sorry if the drawing is a bit big this damn fake computer im useing wont let me change it.

[Skean Dhu]

an interesting read, although it is more for rifles, I'm sure its easily adaptable for handguns
http://www.lindsaybks.com/bks6/rifle/index.html

I am in the process of building a small hobby foundry and i have been considering casting my own handgun blanks which would make an improvised weapon such as this even more reliable

[keith]

Jonesy, I will mail you the gun itself if you would like. I'm not paying shipping though. I dont want it anymore and I have lost the spring that operates it. It is a bitch to operate and gives you one hell of a sore wrist but if you want it it's yours. I'll take pics and post them using my friends computer but I'll have to get him a membership on the E&W forum so it'll take sometime. You had alota spelling mistakes. Im a bad speller too so it's ok but I dont want to mail the gun out of the country is why i mentioned that. You dont live down under do yeh mate? I'm in the states.

[guerrero]

Zaibatsu, of course you are right. The construction of the Astra is not adecuate for a cartridge like
.45 ACP or even mor powerful. The 9mm Para ist on the limit for this type of construction. But
what´s the advantage of the .45 compared to the 9mm? The 9mm is verry powerful. The bullet energy of the .45 ACP is nearly the same, it is more expensive, heavier and in most parts of the world mor dificult to get. Besides the capacity of penetration of the 9mm is superior to the .45. For me, the most important aspects of a handgun are that it is reliable and works well and the access of ammo. The energy is important but I think, that the energy of the 9mm is sufficient for defence. Both handguns in 9mm with an unlocked system which I know, the Astra and the Heckler&Koch VZ70 work well. The only disadvantage is the weight and the strong spring, but for a “real man” with strong hands normally that is no problem. The advantage would be the simplicity of construccion. There exist another pistol model, the german “Sauer 1913”, which I have in my collection. It´s a pocket pistol cal .32 ACP with a simple design and a hammerless construction (SA). The slide consists of a receifer tube and a simple breech block. I think, these three well working constructions (Astra, Sauer1913, VP70) contain a lot of interesting elements for designing a nearly ideal improvised handgun.

[john_smith]

Also 9mm is usually the most easily available cartridge in countries that restrict ammo sales, because the army uses it. A kewlish idea about construction: maybe a delayed blowback system like on Steyr GB could work? It looks like it could be made from a couple of concentric pipes. Sealing it might be a bitch, though.

[A-BOMB]

Just a thought does this gun have be semi-auto? A winchester lever type action is very easy to make, and has the added feature of a breach that is locked shut while firing (good for silencing) it also can be fead shells from a clip or tube anywhere round the barrel it could have a gravity mag like in the british bren gun or a side mag like in the sten. If you need to know anything about a gun like this go to google and search under the smith&wesson "volocanic pistol" it was the first pistol ever to have a caseless round it fired a lead mini-ball that had the powder and primer in the end of the case, it was similar in form to the 'gyro-jet" round from the 1960's just a 130 year earlier. And that was your tales of the gun history lesson for class.

[xyz]

A-BOMB, even if it doesn't get used for this thread, I am still interested in your design and I'm sure that others would be too.

[pest3125]

If the purpose of this pistol is to get a better firearm but we don't want a single-shot "Liberator"
style pistol, how about a 4-shot multibarrel derringer like the LM4 and LM5 "Semmerling" pistols?
The striker mechanism to fire each barrel in sequence is tricky, so maybe we can make it
a "manually operated" repeater" - the striker is in one position, so the 4 shot barrel block can be slided up, rotated and put back in to fire the next shot.

There was a very small 2 shot derringer made by "Feather Industries" (now discontinued) that
worked this way - after firing one shot, you'd simply slide out the barrel block, flip it, and slide
it back to fire the next chamber. You can also buy a spare barrel block and preload it.

[Narkar]

If you want a reliable handgun you could try a revolver. Easyest to build should be something like Nagant(solid frame and fixed), where the reloading was done one-by-one via a loading gate at the right side(could be a problem since its slow). Or the break-open. Something like Enfield or Webley.

[zaibatsu]

Skean Dhu:

That book is available in the UK via a different retailer. I've been thinking of buying it, but not managed to get round to it yet. Hopefully I'll soon own it.

guerrero:

I think the wound channel caused by the bullets is very important. Penetration is a relatively bad thing in this situation, as we'd want all energy to be expended in the body, and any half decent vest will protect against 9mmP anyway, so it's not of a great advantage in that respect either.

I have a book detailing some pocket pistols, I will look that one up. Check out the "little tom" pocket pistol for ultimate simplicity in the trigger mech though.

john_smith:

That's not correct in all countries. Some forbid the use by civilians of the same ammunition as their army uses.

A-BOMB:

Have you seen the book by Walter Muller? That's got complete blueprints for a falling block rifle, but it seems quite complex to make. It is very complete though. I believe semi-automatic to be important in this pistol, as if this was used in my percieved situation (Urban operations) a follow up shot or two could be very useful. Plus, better to try and advance peoples ideas a little. Naturally though I am interested in all firearm-related projects you do :)

Jack's Complete:

Skean Dhu was, I believe, talking about frame blanks, not cartridge cases. Rifling machines don't seem difficult to construct, but the deep hole drilling bits do. I've got a booklet with some diagrams in, although no scanner at the moment. I've also had a new, improved, idea for delayed blowback, which I will detail at the end of this reply.

pest3125:

The hardest part of this pistol I'm thinking of is the trigger mechanism, everything else is just tweaking. The firearm you describe seems to have a complex trigger mechanism with little advantage.

Narkar:

Yes, a revolver may be stronger than a self-loading pistol, but it would be very difficult I think to make sure all the chambers are alligned correctly with the barrel, and require more machining operations than a self-loading pistol.

All:

I've been working on a new idea for delayed blowback. I'm still messing with a 2D cad program so no diagrams at the moment, but I'll explain the concept. The barrel of the pistol is fixed, threaded to a block which is pinned to the frame, with a spring around the outside of the barrel. To visualise what the block would look like imagine a one piece scope mount. Now, in the middle, or the gap between the two "rings" would be a metal sleeve, free to rotate but not move much forward and backwards.

This sleeve is a piece of metal tubing with a helical cut in. This helical cut would be, say, 4mm wide which corresponds to a threaded pin in the slide. When the primer is struck, and the bullet accelerating, the slide starts to move back, and the threaded pin must rotate the sleeve round till it is at the end, at which point it can move off the sleeve and recoil fully. At the end of it's travel, the spring around the barrel brings it back forwards, and the whole thing is ready to go again.

The reason I devised this method is that it seems fairly simple to make, reduces the height of the slide from the fram due to no extra space free for a dropping barrel. Also, a fixed barrel contributes to accuracy and easier stripping. I am also designing a new upper to fit to it, so it can function like a compact, closed bolt machine pistol. The new upper will bolt onto the frame, incorporate and internal overhung bolt, and use the existing magazine feed and hammer. Ideally it would use the same frames as the pistols, but I'm not sure that's possible with the hammer mechanism, but they should be extremely similar.

So, more feedback appreciated.

[bigshoe]

Hey why not just go down to the shops get a meat pie and one of those shitty little chinese cap gun revolers?
Then go home take it apart and work out how big you want it and make a formula for blowing up the parts (into a blue print off course) then as you lay the parts out on the table and finish your meat pie. Think about what types of mateiral you whould replace everthing with.

In this type of gun we would see no mags and none of this extraction crap. The only problem that I can think of is that the barrel lining up with the bullets would have to be dead on.

Remember that revolers came out long before the other hand guns.

[xyz]

bigshoe, I can tell you have no idea wtf you are talking about. A semi automatic pistol is much easier for the home builder to construct than a revolver.

Why bother getting revolver blueprints from a shitty cap gun when there are plenty of already drawn up semi auto blueprints available free on the internet?

Read Home Workshop volume 2 to see just how easy a semi auto can be to construct, and this thread is all about making it even easier.

[bigshoe]

I see that you have no idea what your on about. First rule in engineering, keep it simple. Know why the hell would you make a semi-auto like a redneck that has all the abbilty to rattle appart in your dumbass hand and blow your fingers off. Getting you in time for the six o'clock news looking like a retard?

If you all think that just because you have your blueprints that it will make it go smoother then you got real problems. Even an idot has more of a chance recognising that somthing with more parts is gonna go up shit creek faster.

Let me ask how many of you have a metal lathe, a mill, a drill press and a oxy-torch. I reckon about three, but hold on you can get your hands on them in a friends work shop? well thats ok but there is alot more chance or you getting caught making 16 parts instead of 5 (keeping in mind that you will screw most of the complex parts up more than once).

Aslo xyz let me ask you this, you got a engineering certifcate sunshine? Well I can tell you that I do and learning crap from a book isn't skill.

So maybe you could consider not asking me like some little smart arse if i have any idea, you have no clue.

Sorry if i spelt any thing wrong guys but I dont sit inside on the computer all day like a nerd. Unlike the rest of you I'm no fence sitter.

[Rhadon]

Bye bye...

[smokepole]

XYZ

You said to read Home Workshop volume 2 to see just how easy a semi auto can be to construct. Where can I find a copy to download. I have been looking a enlarging some pinfire guns (like the Kolibri 2.7 mm to .22)

[xyz]

There is a copy on the FTP, I don't know of any other places you can download it from.

It is basically a design for a simple semi auto pistol that has interchangeable barrels and magazines so that it will fire .22LR, .32ACP, and .380ACP. It also has information about a single shot design for handling more powerful cartridges.

[Bigfoot]

For those looking for a "quickie" improv pistol, and don't mind single shot, PMJB Vol 2, p.67 has a brief article on using a 25/26.5mm flare pistol as a foundation. SWIM that I met made one/showed it to me, test fired it with a .22 rimfire cart. She used a British flare pistol, a 26.5mm to 12 ga adapter from Orion Signal, and a .12 ga to .22 adapter from http://www.mcace.com. Not bad little shooter, and just like the PMJB article said, contact silencer.

[guerrero]

Zaibatsu, I hope you´ll excuse me, but again I have to defend my favorite handgun cartridge 9 mm Parabellum. Of course, the normal FMJ bullet does not penetrate modern safty vests and although its stoppingpower isn´t very high. But with a hollowpoint bullet its stoppingpower is very high and there are although penetrator bullets. The french THV e. g. is very effective in both aspects (at short distance): It is an extreme manstopper and penetrates most types of safty vests. I don´t know why they stopped the production. If you want a handgun cartridge which is very effective in both aspects and as well for distances of more than 50 yds, I know only one: The 4,6mm For the PDW of Heckler&Koch. It´s the very best choice within a high penetration capacity and stopping power up to 200 yds. and a very low recoil. It´s only disadvantage is, that for civilans in the most parts I know it is almost impossible to get it because it is relatively new and till now don´t exist any civil handgun in this cal. (as I know). Therefor I think The 9 mm Para is still the best choice because of it´s ballistic capacity and accesibility.

[FragmentedSanity]

There is an active thread atm called Weapon Plans. In this thread is a post by a member called Garbage - which links to a web page with a couple of downloads - those being the .22 machine pistol and the two pistols out of Homeworkshop 2 - the zips arent the best but they are available without FTP access.
I could post a direct link - but If you cant find it yourself with those instructions then you dont deserve the files or more likley couldnt read them anyway.

[zaibatsu]

bigshoe:

I have a Saxby and Palmer air cartridge revolver which I could dissemble to get some dimensions. They are (in contrast to Brocock revolvers) very sturdily built, having been built upon similar tooling to real revolvers. Unfortunately they are no longer in production and now being outlawed by the government. I do understand the benefits of a revolver, but I don't think they are the most appropriate for home manufacture.

The chamber of a self-loading pistol can be accurately centered using a lathe, whereas the line up on revolvers, while possible, is more troublesome, and an off-center hole could be disasterous. The high capacity of most modern semi-automatics is not necessary for police, but I feel it would be for people operating outside the law, if only to provide covering fire while attempting to escape.

Guerrero:

Of course I welcome and anticipate your views, as you understand what you are talking about. I've seen pictures and reports on the french THV, it is very interesting, although I'm not looking for a long range pistol cartridge. I'm not looking to make this pistol into a PDW, as the old saying goes " A jack of all trades, a master of none". However, if we remove ourselves from the debate on the 9mm P, you will appreciate I hope that it is far better to have a system capable of handling higher powered cartridges.

In my mind, I see the dual armament of a semi/full automatic carbine handling large calibre pistol cartridges and a handgun. The extended tube of a carbine would really boost the velocity of the cartridges, and the handgun would not need to be too long range. The carbine would employ a type of dealyed blowback I'm thinking about currently, similar to the useless Blish lock on the Thompson smg, but hopefully a little more effective.

As to the .45ACP or other larger calibre pistol cartridges, I think it is a lot more damaging to the person it hits, and has a higher chance of breaking bones through a ballistic vest than the 9mm P. 9mm P cartridges that have a hot loading do expand quite well, but I think the same is true of the .45ACP. Also, the type of recoil system I am talking about would allow the pistol to be made in a much more compact form without having it extremely heavy. Also, realise that while the 9mm P is a better choice for calibre because lots of military units use it, but while you may be able to aquire military surplus rounds, they will be FMJ and therefore not very effective.

[NickSG]

The 9mm is IMO a much better choice than the .45 for many reasons. First, it allows more rounds in a smaller magazine. Second, it gives better penitration through barriers and flesh, not to mention it will punch through a steel helment at 4 times the distance of a .45. It has less recoil, less noise, and less muzzle flash so you can operate it easier, and not deafen and blind yourself while shooting at night. Its is also nearly twice as light, so you can carry more ammo.

[Bigfoot]

For the record, and any firearm neophytes who bother to read:

It is true that the revolver predates the autoloader. But the concept took several years of R&D to become functional. The reason the wheelgun had to come before the autoloader is simple: ammunition. The ammunition at the time was loose-component: percussion cap, powder, and ball. An autoloader that could handle that would be impossibly complex. But the revolver is essentially a multiple-chamber firearm, whose chambers are loaded in advance. Hence, when cartridge ammo was introduced, adapting the revolver to use it was fairly simple. The development of an autoloader was dependent upon reliable cartridge ammunition, using clean-burning powders.
Note: clean is a relative term.
Part of the initial slowness to adopt the autoloading pistol was due to the need for much TLC to maintain reliable function, especially with propellants available during 1H 20th Century.

Sam Colt today would favor the autoloader for its simplicity of design and manufacture, and reliability. After all, he designed the revolver for antipersonnel use.

So everybody cut it with the suggestions for a homebrew revolver already!


I assume it's pretty obvious why we're not discussing pump, lever, or bolt-action repeating pistols. Although the lever could be a viable pistol option, if designed for use in Governor Schwartzenegger style (T2).

[Jacks Complete]

Bigfoot,

What you say about the history is true, however, for personal defence, I would always choose a revolver as my back-up gun. I would have a revolver as the backup gun to my semi-auto pistol.

The semi is great for high capacity and faster shooting, but the odds of a revolver failing, even after much abuse, is far lower. After all, semi jam, rounds fail to go off, etc. With a semi it is two hands to fix, and precious time. A revolver lets you thumb the hammer (or just pull the trigger) and try again. And again. And so on. The semi leaves you looking like a right noddy for your last few seconds on earth. The revolver gives you something to talk about later ("Sodding cheap ammo went click!")



Swerving dangerously back to the topic now...

I thnk arguements over the calibre are silly, since the design will be for a semi-auto centerfire pistol - makers will choose whatever ammo they have access to, be it 9mm, .45, .357 or .44, or even odd stuff like downloaded .223 or 6mm pinfire!

What we need to do is come up with a good enough design that it can handle whatever is asked of it. Perhaps the only thing to settle is the "rimmed vs. rimless" debate, since extraction is different on the two types.
Normally rimless cases, like .45 and 9mm are used for semi-autos, but I don't have any access to them, so the design would be far better being something like .38, a great revolver cartridge, but rare in semis due to stacking and feed problems due to the rim.

What we should work on is the system spec, not the detail!

We need to quote on what capacity of mag., what style of mag, size, barrel length, action type, and design it from there.

I vote for a fairly short action, suitable for rimmed ammo, (.38) in a 1.5 stack, holding about 10 rounds, barrel about 4.5" and locked to the frame (not moving under recoil) with integral muzzle brake and hopefully some kind of delayed blowback.

Do we want it to be a standard-ish design, or do we want it to be something radical, like ultra-high cap mag., front grips, empty case storage?

I like the idea of all three of those, in quite a radical design.

We could design it to be caseless, or semi-caseless, but I doubt it would be expediant.

Thoughts? Ideas? Suggestions?

[zaibatsu]

Jacks Complete:

While I admire your wish to get the topic back on track, calibre does have implications - higher powered cartridges change the type of action we could use. The lower power the cartridge, the simpler it'll be to build.

Also, having a revolver as a backup to semi-auto seems a little daft. The trend in law enforcement is to to use smaller models of the same semi-auto handgun. Think about - same controls, can use the same mags, some similar internal parts. I guess it's all about interchangibility.

But, that aside, I admire your attempt so I'll join in!

Calibre: .45acp, or 9mm P

Magazine: single stack

Size: big

Barrel: 5"

Delayed blowback through the sytem I previously mentioned.

Reasons for my choices:

Calibre: Only real choices for calibre in an handgun which intends to be reasonably powerful. Rimmed cartridges weren't designed for self-loaders, learn from that. If you are in the UK, and have access to .38, then you've got access to rimless cartridges.

Magazine: increases reliability, which is nice to have in an improvised weapon.

Size: Having it larger means less risk, as it will generally be stronger. Also, it's a lot easier to make.

I'll be interested to hear what other people think.

[Jacks Complete]

Hope you don't mind this style of reply.

Jacks Complete:
While I admire your wish to get the topic back on track, calibre does have implications - higher powered cartridges change the type of action we could use. The lower power the cartridge, the simpler it'll be to build.

I realise that, but the difference in power between 9mm and .45 isn't enough that radically different designs will be needed.

Also, having a revolver as a backup to semi-auto seems a little daft. <snip>I guess it's all about interchangibility.

I would go for a seriously big revolver for my back-up gun, if I were in a position to do so. Purely personal preference. :) .457 Casull or some other "wrist breaker". If I ran out of 9mm and/or the guy was wearing some kind of armour suit, I might just need it, as either we wouldn't be in Kansas any more, or my other gun broke. Of course, I would also choose when to use it, as it is a fully functional cannon on it's own, and then, of course, the semi is the back-up gun.

But, that aside, I admire your attempt so I'll join in!

Calibre: .45acp, or 9mm P
Only real choices for calibre in an handgun which intends to be reasonably powerful. Rimmed cartridges weren't designed for self-loaders, learn from that. If you are in the UK, and have access to .38, then you've got access to rimless cartridges.

Agreed. Not so sure about availability of ammo, but YMMV to mine. As a choice of the two, I would go for .45 ACP. More intimidating to look at a .45" hole, and the pressures are lower, plus the round is subsonic, and so can be fitted with a silencer, which is important for practise, etc. when the sentence is 5 to 10 years for simple possession! (.45 is 11.48mm)

Magazine: single stack
increases reliability, which is nice to have in an improvised weapon.

I agree regarding the reliability, but I think that 1.5x stack should be quite possible. Some reading and experimenting may be required.

Size: big
Having it larger means less risk, as it will generally be stronger. Also, it's a lot easier to make.

Agreed. Obviously too big would be clumsy and obvious, but again, it is more intimidating.

Barrel: 5"
Delayed blowback through the sytem I previously mentioned.

A 5 inch/127mm barrel will be quite tricky! That extra half an inch means that drill bits are suddenly harder to get hold of. It will be good for accuracy, power and pointability, though.

Delayed blowback, for reasons as above - Agreed.

Ok, so, how do we go about making the important parts?

http://custom1.farnell.com/cpc/product.asp?catalog%5Fname=CPC+Catalogue&category%5Fname=Tools+and+Maintenance+%2D+Tools+%2 D+Hand+Tools+%2D+HSS+Drill+Sets&product%5Fid=274284
is a nice drill set in Cobalt Steel, which includes both 9mm and 11.5mm bits. I haven't found anywhere that sells 11.5mm long or extra long bits, and the 9mm only comes in long. Sadly, the CPC/Farnell site fails to mention the (second) most important bit, which is how long the bits are!

AmmoGuide tells us the bullet for .45 is actually 11.48mm, and the case is tapered from 12.01 to 12.09mm, and 22.86mm (.9") long. Hence we need a drill bit that is 4.1" (104mm) long and 11.5mm dia. if we can drill from both ends. From the other end we can drill with a 12mm bit, and only drill down 0.9", and it should be fine.

Anyone want to work out barrel wall thicknesses, etc.? I am going to bed...

[zaibatsu]

That style of reply is good, it makes it easier for me!

Point 1: Difference between 9mm P/.45ACP not enough to change design

I don't agree. As posted before, 9mm P handguns have been made with blowback, just with a big spring. I don't think .45ACP could do that, but as we're both in agreement on delayed blowback, it's a moot point.

Point 2: Big revolver as backup

Well, at what point does a back-up gun become a main pistol? I assumed it was believed that a back-up pistol shouldn't be bigger than the original handgun, but the definition of back-up includes it I suppose. But I know this, if we both ran at each other, got within 10m and found our rifles were empty, I'd rather pull out a double-action glock 33 than have to swing a heavy single-action revolver onto target.

The fact that you need a back-up pistol in an urban situation (which is most likely) tells you trouble is close and fast. You need to shoot quickly, and come back on target quickly. If the guys wearing a vest, I'll shoot for the head, or mix my ammo with some AP rounds. Moot point again though, as this isn't being designed to be a back-up pistol, although I believe my design allows this.

Points 3: Availability of ammunition

I'm sure you can have access to pistol ammunition within a couple of days. Don't forget all components of a pistol round are available legally and without the need for a licence, it's just putting it together that causes trouble... We can't buy any ammunion designed to expand in the UK though, which makes me wonder about swaging weaknesses into a FMJ.

Point 4: Diff calibres

The pressures are lower in a .45ACP, but a .45ACP will give the frame a bigger hammering than the 9, which means you have to have to be more careful with the manufacturing. The easiest way for most people to get ammunition is through reloading supplies, so the people could load up subsonic ammuniton. Although a silencer would be most useful for practising, but wouldn't replicate completely the handling of the pistol, although it would be nice to just have the pistol :(

Point 5: "Double" stack mag

My reservations on this are for a couple of reasons. The first is that I expect it would be more complex to manufacture, and would take a bit of experimenting. Not out of our league of course. But the second is something I read in a Bill Holmes book, that I'd never considered before. What happens if you drop a pistol with a double stack mag and the bullets rearrange themselves in the mag?

Point 6: Barrel length

A 5" barrel will come from a much longer barrel chopped down, allowing one place to manufacture barrels in quantities sufficient to supply a couple of workshops finishing the pistol. The barrel will be bored with a deep hole drilling attachment on a lathe. All the parts for the deep hole drilling attachment can be made on the lathe, and possibly a bit of milling.

Now, about making the pistol. As stated at the beginning, zip guns are fine, but they are not this. But the different parts of the pistol are coming into my head like this:

Slide - pressed steel, with the internals made of steel attached through something like threaded bolts.

Frame - Made from laminated steel sheets cut to correspond to part placement, could be constructed in many places through the use of templates pasted on and roughly cut to shape, and then taken to spec with a file. If found who would think they were for a real firearms - "Just making some toy guns officer"

Magazine - pressed steel

Barrel - As previously mentioned.

Internal parts - I dunno, the most difficult bits will be in the trigger mech, everything else can be made by hand or through the use of a mill and lathe.

I don't know about barrel thickness, but something like 4mm should be fine for 9mm I think, depending of the quality of the steel.

There's my next installment :)

[JoeJablomy]

Zaibatsu: a few concerns
Barrel: Why deep-hole drill a long barrel blank just to cut it down? Deep hole drilling is very specialized, and making a deep-hole drilling rig to do a 30" barrel would seriously increase your capital costs over one for 4" or 6" barrels. Doing the barrels individually would increase the number of operations, but would also reduce the amount of effort to drill each inch of bore and reduce the number of screwups.

Frame: The laminated sheet metal thing probably works a lot better if you have a giant sheet metal press. Also if you have craploads of sheet and plate around. Cutting all the plies by hand would be nearly impossible unless you can drill them in jigs early on and rivet them together before finishing them with a big f*cking grinder. Even so, shear strength between the plies would of course be no more than that of the rivets, i.e. much less than solid metal, and structural sections would probably have to be very thick or have very complicated, hard to produce shapes, so the product might weigh a lot.
I would reccommend that parts like the grip frame and such be machined from chunks of aluminum (much like that guy did with the AR-15 receiver), and the frame rails milled from steel bar or pressed and ground to shape. A lot of the contouring and such on the aluminum could probably be done by hand, perhaps by the end user.
I'm kind of attracted to the idea of pressing metal with a hydraulic jack or the equivalent, but I'm still pretty worried about the dies you'd have to make. How many gun parts are machined and how many are more economical to press depends on how many guns a given person wants to produce, so for personal use a single gun should be all-machined, since the dies would be useless evidence after one use.

Slide: How do you plan to make this from pressings? I don't think anyone else has ever done it, although I could imagine using tube stock.

Operating principle: I really like your idea, but I'm afraid the sleeve would have to be made very thick around the barrel because of the groove in it. If the groove cuts all the way through, the sleeve might not be strong enough to stand up to recoil; if it doesn't, the sleeve will probably be at least 4-5mm thick on top of the barrel breach, meaning you have a pretty big gun.
Also, have you heard of some of the newer makarovs where they cut threads inside the chamber to grip the casing while it's under pressure? It's a very crude idea, but very simple.

[zaibatsu]

JoeJablomy:

Firstly, the pressed slide. Sig do it, I believe either walther or mauser started doing it around the 1950s. If you think about it, it is just a metal channel, with the differences being metal blocks than you can attach to the slide. I should think a 4mm slide should be sufficient, although experimentation would be necessary.

Secondly, the deep-hole drilliing. I'll discuss that a bit more once I finish something I'm doing, that should reveal a bit more on the process.

Thirdly the frame. That's just my idea of how to speed stuff up, and not have to do a lot of internal milling. I think it'd only have to be made from 4 or 5 plies of relatively thick metal, and I think if you use steel, it shouldn't be significantly thicker than a commercial design, and if aluminium frames can handle the wear and tear, I should think a laminated steel frame can do the same.

Fourth, the delayed recoil idea. I don't think it will make the pistol too big, at least not from the plans I've drawn. Don't forget that the barrel itself won't move, so unlike a conventional browning system you don't need to allow space in the frame for it to drop. What size walls do you think the barrel should have around the breech area?

Fifth, the amount of dies needed. Yes, there may be a lot, but what I was thinking was to find ways of producing fairly similar pistols in a semi-mass production. If people have access to better tools then that's fine, but I'm trying to find the most simple ways of doing things.

Great to hear more input into this.

[NickSG]

A double stack magazines reliability would be questionable, but a 1.5 stack magazine would be much more reliable like mentioned above.

With a 1.5 stack magazine, the inside diameter of the magazine is 1.5 times that of the bullet. This allows the bullets to rest on eachother, but not beside eachother. Feed lips can be made for the magazine which also increase reliability (take a look at Glocks magazines).

[Jacks Complete]

Point 2: Big revolver as backup In certain situations, I would use it as the primary, as it wouldn't leave a shell casing behind! Also, for intimidation, you have the step of cocking the hammer, which, like the slide on a pump gun, must surely be a pants-wetting experiance when aimed at you...

A double stack magazines reliability would be questionable, but a 1.5 stack magazine would be much more reliable like mentioned above.
Agreed. It also increases the ammo capacity, which is good. Most modern after-market mags are 1.5 stack, from what I have seen.

Secondly, the deep-hole drilliing. I'll discuss that a bit more once I finish something I'm doing, that should reveal a bit more on the process.
If it is a way to make deep barrels without the need for a lathe, excellent. I have a well-stocked toolshed, but no lathe, and no milling machine. Having said that, I think I would make a 5" barrel regardless. Why waste barstock? Another option might be for a longer thicker bar, and to turn it so that there is an internal cavity, then turn down the outside, forming an integral silencer. Obviously this could only work with some way to bore a very long hole! (and centrally, at that) It would be kind of like:

==============
=======\ |
\______|

so that the supressor was actually built in, perhaps in a triangular shape, or perhaps in the form of a long hole off-center, then a much larger hole centered on the bar, then the rest of the bar either turned or cut away.

As regards the pressing of stuff, I have bought a 4 ton hydraulic jack, and am looking at turning it into a barrel sleeving machine, or some kind of press. In another thread I posted the link, MachineMart, and they sell up to 20 ton off the shelf. Of course, pressing is a bit tricky, so multiple tries will be needed, and making the forms will also be tricky, as it will require either milling or grinding the steel forms.

Without messing about with a press, you can fold and bend up to about 2mm steel with a hammer and a good bench vise. It would be a bit slower, but for a single operation you wouldn't require so many tries, and you would soon get good at it. A simple tap and die set will let you then use threaded rod to hold the thing together nicely. Another way would be to do as Luty did, and use preformed steel tube, and cut or grind it.

Personally, I would stay away from building forms and pressing. It may be that several other ways to achieve our aim are possible.

As for building a form or body out of laminated steel, I think that would be more complex than most ways. It would take a lot of work to get them arranged correctly - It would probably be as easy to do the tap and drill thing. Also, there is little that would need a laminated approach, and it is used commercially mostly for the money saving. I would prefer to work on a solid block, and use a Dremel or other grinder to remove the metal that way, as I would likely be using a Dremel tool to cut each layer of the lamination anyway. An alternative might be to cast it out of brass, which would be plenty strong and heavy enough.

NickSG, the idea of cutting grooves into the chamber to delay cycling may sound good, but I think it will wreck the brass, and cause a whole lot of grief with the action, as it snags. Also, forensics would match you to it far more certainly with chamber grooves. (There is a company in the states that now offers micro-machining of ID numbers into the chamber, stamping every case on firing!)

[NickSG]

The feed lips are on the magazine, not inside the gun. They act as a kind of "funnel, so that only one round is fed at a time.

As for the wheelguns, I occasionally carry a .44 magnum (S&W 629 6 1/2 inch barrel). Thats what i call intimidating! :) 300 grains of lead traveling 1175 FPS will take care of anything (its also a great hunting round).

[Jumala]

Does anyone really want to make own barrels? I doubt that someone can make a useful barrel, rifled, polished and with the nessesary precision at home. The material for nitro barrels is a very hard stuff, too hard for many standart tools.
I´ve tryed to make a little blackpowder barrel a lot of years ago.
I used a lathe to drill and ream it. The result was bad. The inner surface was very rough.
Now I buy my BP barrels I need here

http://www.lothar-walther.de/

They have really all kinds and calibers. The only annoying is the price.

[NickSG]

The barrel doesnt have to be rifled but it helps. With a smooth bore you should still be able to get reasonable accuracy out to about 25 yards, that is, if there is a tight fit.

[zaibatsu]

It's 5:30am, I've just got in, and my hangover has already started, so please bear with me if my replies are a little lacking.

NickSG:

What Holmes described was the gun being dropped, the spring compressing itself, and the rounds rearranging themselves in a pattern that doesn't feed. To me it seems feasible, although whether the disadvantages outweigh the advantages, I don't know.

Jack's Complete:

You can rifle barrels without requiring a lathe or milling machine, but to make the rifling machine you need a lathe/mill... catch 22 but I'm afraid there isn't much other way to go, if you want an accurate barrel. I've got some info at the moment to make a hydraulic rifling machine, but I want it to be complete before I post it.

I'm not an engineer, but I wouldn't like to make the type of barrel/supressor combo you're talking about. It's a little pointless, and would require more operations. A simple supressor should be a quick task for someone with a lathe, or even with just some tools.

I think you could cast the fram from aluminium, but you can't ensure there are no voids in your casting. Brass seems a bit of a strange choice for a frame, that gun is going to be *heavy*.

Jumala:

If walther would export to the UK, I'd be very happy. Unfortunately they don't, even though unchambered barrel blanks aren't restricted in the UK.

NickSG:

The riflings the relatively easy bit. Getting the barrel to the required diameter and relatively smooth is what causes problems.

[Jumala]

Yes, smooth bore barrels can give good results. I have a .75 flint lock musket. With a well patched and greased round ball I can hit small targets at 100m distance.
In modern weapons the bullet will be pressed through the barrel. If the inner surface (rifled or not) is rough a lot of copper from the jacket or lead settles in the barrel. It becomes harder and harder to press a bullet through it.
I bought once a .31 blackpowder barrel from walther. A 50cm long piece costs approx. 40$. The inner surface looks like a mirror.

Edit:
Walther´s homepage supports several languages. No need for that if they sell only in germany. I think there is a distributor or something else in UK.
Here is an overview in english
http://www.lothar-walther.de/english/indexaz.htm

[zaibatsu]

All I know is that I emailed Walther asking for air rifle barrel blanks, and they asked for a firearms licence, perhaps it's possible they didn't understand me, although the quality of the english in the reply was good.

[MP5Guy]

http://www.ershawbarrels.com/

MP

[Jacks Complete]

Comments:
http://www.border-barrels.com/
Based on the England-Scotland border these guys have a crap website with great content. The articles on barrel making I have already saved out - lots of interesting history and technique. They use both cut rifling and button rifling. Stellar reputation, very very good barrels.

http://www.lothar-walther.de/english/info.htm
Better designed website, some dodgy English, based in Germany. Use button rifling. Little technical detail.

http://www.ershawbarrels.com/
Slightly heavy website, but useless for content. Based in the USA. By far the cheapest of the three.No Technical details that I could find.

[JoeJablomy]

zaibatsu: I tried to post this yesterday, after a few days away from the forum, but my internet connection was out and the fucking forum software is really good at losing information entrusted to it. So I'm probably forgetting something.

1. My specific worry about the 'delay collar' or whatever we'll call it is that it will rupture under the stress of firing unless it is built Really thick, in which case the pistol could easily be 1.3-1.5" wide or more. Maybe that isn't unusual, but I thought I'd mention it.

2. The equation for wall thickness of a tube under internal pressure is something like

t= 2rp/S

where
t=wall thickness
r=bore radius
p=max operating pressure
S=tensile strength of the steel you use
2=safety factor

Note that this is reconstituted from old, old memory, and so may be shit. It is similar to a rocket casing equation I just looked at, though.

3. I still think aluminum is a better choice for the frame because it's lighter and easier to shape, and could be made stronger. If you cut matching grooves and ridges into the mating surfaces of the parts and epoxied as well as screwed them together, it would almost certainly be stronger than laminated steel. The steel would still be too thin for stuff like this. An alternative would be to press the grip, which has the most difficult contours, as two halves and weld them together.

[zaibatsu]

JoeJablomy:

Delay collar - perfect term for it I think. I've been doing some thinking about this and one potential problem I see, although I still think it's ok, would occur if the chamber walls are too thin, or a very high power cartridge was used in the pistol. This could cause the chamber walls to bulge, and stop the delay collar from rotating. This would at best jam the pistol, at worst force the corresponding pin to snap, releasing the slide too early and damaging the frame. I don't think the slide would fracture and fly off, so the danger would be limited, but something I think needs to be considered.

Anyway, onto your points.

1) Delay collar rupturing: the delay collar isn't intended to hold pressure, the chamber section should be sufficiently sized to hold the pressure. I don't think it should make the pistol too large, because if you look at a breakdown of a standard pistol, the chamber area isn't much wider than the rest of the barrel. From that I'm guessing that the walls can't be too much thicker than the rest of the barrel, so additional dimensions would only increase overall width of the pistol by 8mm, assuming the sides of the slide touch the barrel, which they don't. This leads me to think that the delay collar won't increase the size of the pistol much.

3) Fine, that's still a valid method of manufacturing. I was hoping to find an easier method, but if that's necessary, then that's what we'd have to do. There would still be ways to speed up the manufacturing process, for example making the frame modular like a STI frame.

Everyone else:

Check out the books I'm listing in literature and links, SWIM has got some useful books on barrel manufacture, with a book on a hydraulic rifling machine to follow.

[guerrero]

Has anybody experiences with the accuracy of pistol bullets in smooth barrels? I know that, acording to my experiences, a "Brennecke" gives good results from my shotgun up to 100 yds. Although I think that the design of the Brennecke is created especially for shotguns and a FMJ- or Lead-bullet with round neck is not the same thing. Maybe a wadcutter could be relatively accurate in a smooth barrel. For a handgun acceptable accuracy up to 25 yds is enough, bat what about a submaginegun? I think acurracy up to at least 50 yds or better 100 yds is required. Is that possible with a smooth barrel?

[NickSG]

I get fairly tight groups with a smoothbore 12 guage shotgun out to about 50 yards (with 1 ounce slugs). Ive heard of hunters getting perfect heart shots on whitetail out to 150 yards though.

[MP5Guy]

JoeJablomy:

Delay collar - perfect term for it I think. I've been doing some thinking about this and one potential problem I see, although I still think it's ok, would occur if the chamber walls are too thin, or a very high power cartridge was used in the pistol. This could cause the chamber walls to bulge, and stop the delay collar from rotating. This would at best jam the pistol, at worst force the corresponding pin to snap, releasing the slide too early and damaging the frame. I don't think the slide would fracture and fly off, so the danger would be limited, but something I think needs to be considered.

Anyway, onto your points.

1) Delay collar rupturing: the delay collar isn't intended to hold pressure, the chamber section should be sufficiently sized to hold the pressure. I don't think it should make the pistol too large, because if you look at a breakdown of a standard pistol, the chamber area isn't much wider than the rest of the barrel. From that I'm guessing that the walls can't be too much thicker than the rest of the barrel, so additional dimensions would only increase overall width of the pistol by 8mm, assuming the sides of the slide touch the barrel, which they don't. This leads me to think that the delay collar won't increase the size of the pistol much.

3) Fine, that's still a valid method of manufacturing. I was hoping to find an easier method, but if that's necessary, then that's what we'd have to do. There would still be ways to speed up the manufacturing process, for example making the frame modular like a STI frame.

Everyone else:

Check out the books I'm listing in literature and links, SWIM has got some useful books on barrel manufacture, with a book on a hydraulic rifling machine to follow.

Note the Ball Detent which engages a corresponding notch made in the bolt of a converted Ruger 10/22 Full Auto Select Fire. This is done to stop Bolt Bounce in conjuntion with a Free Moving Weight which is machined in to the bolt itself. The amount of detent pressure is controled via a tunable spring which loads the detent from below. Ajustment is made with a allen wrench.

Just thought this might be an easier avenue to what you are trying to achieve.

MP

http://www.hunt101.com/img/110465.jpg

[Jacks Complete]

zaibatsu,
Delay collar - perfect term for it I think. I've been doing some thinking about this and one potential problem I see, although I still think it's ok, would occur if the chamber walls are too thin, or a very high power cartridge was used in the pistol. This could cause the chamber walls to bulge, and stop the delay collar from rotating. This would at best jam the pistol, at worst force the corresponding pin to snap, releasing the slide too early and damaging the frame. I don't think the slide would fracture and fly off, so the danger would be limited, but something I think needs to be considered.

The "heat" of a set of cartridges is one problem that is really hard to fix in your hardware design, regardless. A low powered cartridge will not cycle the action, and a really hot one will destroy it, as the slide slams back and breaks off or rides over the back, often shattering the slide and/or really messing you up. This, however, needs to be addressed in the reloading stage, not in the hardware design.

I agree that if the design uses the power (case expansion or whatever) to hold the collar until a certain point, a marginal round that fails to make that collar engage fully may shoot you in the head with your own slide! The recoil buffer/spring must be capable enough without the collars assistance. This must be in the hardware design!

guerrero,
I have experiance with smoothbore muskets and pistols. Generally, the most noticable thing about the accuracy is how hard you have to work to get it! Don't forget that the shotgun your slugs come out of has a barrel at least 2 feet long, and a shoulder stock, whereas this pistol will have a quarter of that barrel, at the absolute maximum.

NickSG,
never forget, I can tell you some "miracle" shots I have had, but over the course of the years, you will get some. I once shot a comp at 800 yards, with a total group vertical dispersion of less than 1/4 minute of angle. I put all the shots into the top of the five ring, scoring 48.2. That really shouldn't have been possible with my old rifle, and I did it under competition rules at a major event. Want to buy my rifle?

Of course, I don't tell stories of the times I have trouble holding the black, and I am sure that it isn't me... Nor do those hunters.

Brenecks are only good to 80 yards for most guns. Old patched muskets can be good to 500+!

Anyway, rifling is something you really want, and you should only go smoothbore if you have no other choice.

[zaibatsu]

I hate to keep going over my idea, I think it may bore people, but I don't think you understand it. The delay collar doesn't expand and stop the slide recoiling, it just slows down the slide movement by making it move over a "longer" path. By forcing the peg in the slide which corresponds to the groove in the delay collar to move along the helical path, it has to travel straight, but to do this the collar has to rotate, so that the peg always moves straight. Not quite sure if this explains it a little better.

[Jacks Complete]

All:

I've been working on a new idea for delayed blowback. I'm still messing with a 2D cad program so no diagrams at the moment, but I'll explain the concept. The barrel of the pistol is fixed, threaded to a block which is pinned to the frame, with a spring around the outside of the barrel. To visualise what the block would look like imagine a one piece scope mount. Now, in the middle, or the gap between the two "rings" would be a metal sleeve, free to rotate but not move much forward and backwards.

This sleeve is a piece of metal tubing with a helical cut in. This helical cut would be, say, 4mm wide which corresponds to a threaded pin in the slide. When the primer is struck, and the bullet accelerating, the slide starts to move back, and the threaded pin must rotate the sleeve round till it is at the end, at which point it can move off the sleeve and recoil fully. At the end of it's travel, the spring around the barrel brings it back forwards, and the whole thing is ready to go again. Ok, I think I get it now. I read back over the above, and the rest of the thread again.

The collar has a fairly tight twist on it, so that the locking lugs/pins (or whatever) have to turn it a bit before they unlock, hence delaying the slides blowback for a fraction of a second? Is that what you are saying? In which case, if the pins shear or ride out/over the collar, the energy that would normally be used to turn it would need to be dealt with by the recoil spring.

The collar rotates- In which case, what does the collar hold on to? Is it just round the barrel? If so, two pins would be better, to help balance the torque. Is the collar spring loaded? or is it heavy? Also, binding may be a problem when it gets driven into the rear stop.

It is a good idea, as it moves the recoil gear forwards, which will make it nose heavy, which will counter muzzle rise. I might have to see a drawing before I am totally convinced, though I can see what you are getting at.

[Dave the Rave]

On the rotating collar idea, what about one fixed upper receiver and an fixed barrel, and heli grooves on the bolt ? Maybe one bold made of two pieces, one fixed and one mobile, with the grooves.

When the recoill initiates, the bolt moves rearwards and it´s mobile part is forced to rotate by pins on the upper receiver. The fixed part of the bolt holds two pararell guiding rods, with the springs. As the weight of the recoill is held by two springs, the springs can be smaller and the system is safer.

Part of the force of the recoil is used to rotate the bolt, and then, when the pressure is falls to safer levels, the rotational movement stops and the final recoil works as regular, on an linear path.

The construction of an 2 pieces bolt can be easily done, and the fixed upper can be like the mauser shnellfeuer pistol. Indeed, I think that all the design can be used, as it simplifies the hammer / trigger design, taking out the transmission bar, and making easy the double system, also it puts the magazine in fron of the trigger, which will stabilize the weapon, making it more precise, opening the space to put two springs instead of one.

What do you think ?

[zaibatsu]

Jacks Complete:

I'm working on a simple paint diagram for you. Till then, think of it like this. The barrel is threaded at the breech end, and threads into something shaped like a U, open topped, with the sleeve placed in the top of the U, and the barrel then threaded into the U. The bottom of the U is thick enough to pin it to the main frame. So you place the delay collar into the open topped U, and the barrel then threads onto the U, leaving the collar free to rotate.

You're generally right in your understanding of my idea, which means it can't be too strange. Binding may be a problem, but I'm sure you can reduce the friction caused be the sleeve rotating through the use of some coating, such as hard chroming.

Dave the Rave:

I had a similar idea for a recoil system for a grenade launcher. Basically, in my idea you have a two part bolt you have an "internal" part, which includes the locking lugs and fits inside a second part. Inside the second part are some helical grooves, which correspond to grooves on the internal part. Upon firing the cartridge, the barrel moves back a distance, pushing on the "internal" bolt, which causes it to move backwards inside the second "external bolt". Because of the grooves, it is forced to rotate, disengaging the locking lugs, seperating the two part bolt from the barrel (the locking lugs lock into a barrel extension) which is then allowed to recoil fully.

Inside the "external" bolt is a spring which presses on the "internal" bolt, causing it to move forwards in the grooves, rotating so that the lugs can then move back into the barrel extension. Obviously the main recoil spring is stronger than the "internal" spring, so when the "external" bolt comes back to a ready position it is forced to compress the spring, and in doing rotate the "internal" bolt to a locking position in the barrel extension, ready to go again.

Fucking hell, I need to learn CAD, my English isn't good enough to explain it properly.

[Dave the Rave]

All of us Zaibatsu, all of us...

I also need to learn CAD, my english is awfull and I have an serious lack of words to fully describe my tougths.

But I understood what are you talking about. I like the idea of one inside spring, it could simplifie the idea of rotating bolts, and we can use commercialy made rectangular tubes to uper and lower receivers.

Did you ever reard about one pistol caled the "royal" pistol ? It was made on the shape of the mauser c92, with an fixed magazine, but the main idea is that all the pieces are stamped and the uper and lower receiver were fixed on each other by sleeves and grooves, the only pin being the hammer and trigger pack. It worked on the 7.63 mauser cartridge, but also used the
9mm parabellun.

It´s very simple to build and reliable to use. Maybe we can use some of their ideas, and if you think it´s good I´ll scan and post some pics, plans and the manual.

[xperk]

Jumala,

I am curious as to how you manage to buy from lothar-walther - I thought they only sold to dealers.

Could you perhaps post a german dealer or otherwise reveal the method of acquisition?

[guerrero]

Well, with a schotgun there is no problem. I killed serveral wild boars and a deer with my Remington 870 and Brennecke slugs at a distance of about 100 yds, but pistol bullets are not the same.

[zaibatsu]

Here's a little drawing to clarify what I mean. Please note when viewing this picture I made it with a mix of CAD and MS Paint :) Obviously not to scale, and quality is low because it is unimportant, while filesize is important.

[Jacks Complete]

zaibatsu, can you talk us through it?

[zaibatsu]

Ok, here goes.

Well, the upper most dark grey thin rectangle is the pressed steel, with the lighter grey part on the left manufactured from Al and screwed into the slide. The lower dark grey thin rectangle at the left is part of the frame, ignore that. Now, in the middle of the slide, there is a small light grey rectangle. This is the pin which corresponds to the helical slot in the delay collar.

The delay collar is the the medium grey rectangle with the slots cut in. If you look at the slot you can see the dark grey barrel through it - this is screwed into the light grey "U" shaped piece of steel, which is pinned into the frame. This "U" is threaded straight through, and the barrel screws into this bit.

Surrounding the barrel is the recoil spring. To assemble the barrel assembly, you first place the delay collar into the U shaped piece of steel, and then screw the barrel in. The barrel would probably be pinned into place after this, or fixed with silver solder.

Hopefully this should clarify the diagram a little.

[Jacks Complete]

That seems to make sense.

Thanks.