Brocock revolver conversion to live firing

[tomu]

It is easily possible to fire .22 long rifle cartridges with a Brocock revolver of this caliber. I know of at least three calibres .177 (4,5 mm) .22 (5,5 mm) and ,25 (6,35 mm sometimes designated as 6,5 mm) in which Brocock revolvers are available, obviously it's only possible with the .22 (5,5 mm) to fire real .22 lr cartridges with the help of a special adapter cartridge.

This adapter consists of a round steel body which is turned to the outer shape and dimensions of the Brocock air cartridge. It is much easier to use a thickwalled tube with a 5 mm or 5,5 mm bore and turn it to the proper outside dimensions and after that drill and ream the inside holes. If a metal lathe is not available a tube can be dressed to the proper shape if chucked in a electrical drill and by using a file (lots of skill is required by that way and it’s lots of work).

The adapter is drilled and reamed all way through the middle with a hole of the size of the .22 lr cartridge, if a chamber reamer (Brownells) is availble great, if not a suitable drill and a normal reamer will suffice. The second larger hole is drilled and reamed only partly through, this hole holds the hammer.

The hammer is a piece of small round steel or brass stock with a small firing pin, which is fixed off-center to hit the .22 lr cartridge rim. There two ways to make the hammer. First way would be to drill a small hole off-center in the hammer face and solder/epoxy a short piece of 1 – 1,5 mm diameter piano wire in it, it should protrude not more than 1,5 mm and the striker face should be slightly rounded. The next ways is to cut a slot at the side of the hammer and solder/epoxy in a flat piece of spring steel, see diagrams

Dimensions of the .22 long rifle cartridge and chamber might come in handy for making the adapter. The first number is the maximum dimension of the cartridge, the second number in brackets is the minimum dimension of the chamber, all dimensions are in millimeters (mm).

Lenght of the shell body (L3): 15,57 (16,33), Thickness of cartridge rim (R): 1,09 (1,09),
Diameter of cartridge base (R1): 7,06 (7,32), Diameter of shell body at the base (P1): 5,74 (5,76), Diameter of the shell body at the cartridge throat (H2): 5,72 (5,72).

Different types of adapters can be made. One as described above for firing a .22 lr cartridge, thos adapter can also be used to load .22 blanks with separate bullets if access to .22 long rifle cartridges is regulated by gun laws.An adapter can be made which could use blank firing center firing cartridges and be loaded with a separate bullet also adapters can be made to load a air gun pellet ( BB or Diabolo) and use a center fire primer ( shotgun shell primer or any other type of Boxer primer) for propulsion (see diagrams).

Proper tools, especially drills and reamers can be bought at any tools shop which supplies metal working shops. Drills and reamers are available at 0,1 mm steppings. A very good source for gun smithing tools, like chamber reamers and properly sized drills, is Brownells (www.brownells.com/).

[TreverSlyFox]

Interesting, never heard of the Brocock Cartrage System so I did a little research on it. From the looks of the system your "Conversion" looks quite possible. Off the top of my head I can only think of two or three "possible" problems with it.

1. Chamber Pressure: Your "conversion" cartrages had better be pretty strong of quality steel. A "Target" .22LR, 40gr bullet at 1080 fps developes 26,500 psi chamber pressure and a "Full Blown" .22LR 38gr bullet Super/Hyper Velocity up to 1750 fps has to be pushing at least 30,000 psi chamber pressure. I'm not sure what the Maximum SAMMI listed chamber pressure for a .22LR is.

2. Barrrel throat wear: All pistol barrels have a "Forcing Cone" at the start of the barrel that A. Starts the bullet into the rifeling and B. Compensates for slightly with Out-of-Time cylinders (the cylinder chambers don't exactly line up with the bore). The barrel is made for a .22 cal soft lead pellet expelled at about 410 fps by a "cold" gas. A regular .22LR cartrage bullet is expelled by a "Very Hot" gas at 3-4 times the velocity that the pistols barrel isn't made to take and may well fail in a very short time. It will depend on the steel used by the manufacture of the barrel.

3. Recoil Shock: The frame of the pistol could well be cheap "Pot" metal as a CO2 pellet at 410fps isn't going to produce much recoil. A .22LR may produce a lot more recoil shock to the frame than it's made to withstand. Again it comes down to what steel the maufacturer used to make the frame from.

I think from a safety stand point #1 is your biggest problem to overcome. #2 is much less of a problem other than accuracy over a period of time though that time could be very short. I think #3 falls somewhere in between #1 and #2 but "may" be avoided by just making sure you buy a good quality pistol in the first place to make the conversion with.

[tomu]

Brocock and other Air cartridge type guns are quite popular in Europe, in the UK you will need a licence for them nowadays, but in Germany they can be bought by anyone over 18 years old.

There are two types of this guns, first are real guns converted to Brocock Air Cartridge System and ones which are originaly produced for this Brocock system. In Germany they are called LEP (Luft Energie Patrone). There are also pistols available, but this conversion only works with revolvers because the cartridge shells of the pistol ammo is to small/short to take the .22 lr cartridge and the special striker/hammer. Also the firing pin of Brocock Pistols is flatened so it will not fire a primer or a blank cartridge.

The conversion is certainly not only feasible ,it works. Did it, tested it with several types of Brocock revolvers. With this type of adapter it certainly does not make sense to go to a shooting competition, but for self defence it's ok.

To #1: I'm european so I use the metric system, sorry. A .22 lr cartridge develops a maximum pressure (CIP) of 1800 bar which translates to 180 Newton per square millimeter. Even the softest steel has a tensile strenght of about 330 - 380 N/mm2 and even the more interesting yield strenght for dynamic stresses is over 220 N/mm2. No pressure problem at all with .22 long rifle ammo. So, I would not advice to use high velocity ammo, with short barrled revolvers it wouldn't make sense anyway.

The steel adapter takes all the pressure and distributes it over it's large outside area to the cylinder walls, it's just a few Newtons. The adapter could even be fired without being in the cylinder from a pressure point of view.

to #2: The barrel liners used in Brocock revolvers are genuine .22 barrel liners made of steel and like in all revolvers (and in any other gun as well) the barrel has a forcing cone.

to #3: What recoil? Have you ever shot a .22 lr? The recoil of a .22 lr is so weak, even plastic can stand it. Many commercial .22 lr guns also have a frame of what you call "pot-metal", I know of at least one .38 Special revolver which also has a die cast zinc alloy frame and it doesn't cause it any problems.

The high velocity hot powder gases can and will cause errossion of the frame around and above where the barrel is fixed to it, but with a .22 lr it's not a real problem.

BTW. I made the first prototype of the adapter out of brass because I had the brass round stock at hand and it worked.

[bobo]

One question about .22 caliber though. For my pistol I have different ammo than for my rifle, both are cheapass .22. The gundealer said it was NOT a good idea to use rifle ammo in pistol and vice versa, because the barrel would not withstand it or something. I assume this is what you mean to say about high velocity ammo?

By the way, this conversion has been known for some time by the police, have the brockocks remained the same in the mean time?

[Jacks Complete]

These pistols are a red herring in the UK. After a few were found to have been converted, they were all confiscated, or put on Section 1 or 5, and are now treated the same as a real pistol. You might as well get yourself a Glock 9mm or a Buckmark .22, as the 5 year minimum prison sentence is the same for having a Brocock air pistol, or having an UZI. :-(

[tomu]

To BoBo: Automatic Pistols can be picky about the type of ammo you fire, high velocity ammo shouldn't be fired out of them. It will but more stress on the gun and the gun is likely to jam because of feeding problems.

It's not about the pressure, the maximum pressure of a cartridge is regulated by SAAMI in the USA and by CIP in most other countries, and a gun must be constructed so it will withstand the maximum pressure of the calibre it is made for.

It's a question of bullet weight and velocity or to make it short it's about energy. A high velocity cartridge will stress the gun more than a normal cartridge will do because it develops a higher energy.

To Jacks Complete: It's really a shame what they are doing in the UK. But it's going to get thougher everywhere in Europe. I agree totally with you if one can get his hands on a real gun, be legal or not, I wouldn't bother with converting a Brocock. But getting an illegal gun is not everybodies bussines, one must be afraid not only of police and snitches but also of the illegal gun dealers itself.

So it comes all down to availability and ease of availbility. A Brocock is certainly easier to get than a real gun in most parts of Europe. Brocock's or LEP's (have a look at www.egun.de and do a search for LEP) as they are called in Germany are readily available in Germany for anyone who is at least 18 years old. Btw. parcels send within Europe are no longer subject to customs controlls.

And the real beauty lies in the fact that the gun needs not to be altered and the adapter itself is legal in most countries. As far as I know it is easier to get a licence for a Brocock gun in the UK than it is for the real McCoy, at least one doesn't need to provide a reason for having a Brocock, but I'm not an expert on UK gun laws.

[Jacks Complete]

Climbing K2 is easier than swimming the Atlantic, but you couldn't call either one "easy".

Section 1 (Brocock grandfathering) is fairly straightforward, just have the police come round for an interview, send them counter-signed pictures, money, get a safe, go to a gun club for 6 months, fill out a big form, have your criminal and medical records checked, and more.

Section 5 (where non-grandfathered Brococks are) is a letter from the Secretary of State, and allows ownership of real pistols, machineguns, rocket launchers, etc. I've heard that there are 7 people with these for pistols in the entire country. Even gun shops can't have them! Oh, and expanding bullets live there too, along with AP and explosive and incendiary rounds.

[bobo]

LEP = Luftenergiepatrone

As far as I can see these are conversions from live guns to airguns. Not that I am familiar with german law, but doesn't the conversion to normal weapon include making it permanently useless for live ammo? Are you saying any LEP be remade into a live firearm as long as it's 5.5 mm?

[tomu]

You are right on both assumptions.

Brocock/LEP revolvers in .22/5.5 mm calibre can be made to fire live .22 lr cartridges with the help of the above described adapter without making any modifications on the gun itself.

[tomu]

Because of numerous requests for the graphics I post a download link of the sketches:

http://rapidshare.de/files/27105290/brocock_adapters.jpg.html

[oxbeast]

It's interesting to note that many of the LEPs posted for sale on www.egun.de are actually real firearms that have been converted to LEP.

The little (originally .38 spec) Derringer is very nice. I see it's current owner payed €190 to convert it to LEP.

The Titanium coated Walther is a crying shame !
Sad to see people had to do this to functional firearms.

[sibear]

Sadly it is no longer possible to get a section 1 license for a Brocock (or any other air cartridge) pistol/rifle in the UK anymore.

Applications for existing owners had to be in by January of last year (or was it the year before). It is also ilegal to sell or transfer said weapons.

As for getting them sent in from mainland Eurpope; if you could find someone willing to do it, all overseas parcel post is x-rayed and dog handled. Almost impossible to get one in.

That said there are something like 25000 unlicensed Brococks still in circulation.
The adapter conversion works perfectly with brass and steel as a UK Govt firearms supplier informed me.

[Jacks Complete]

It's not sad, they have a place. You can't practise with a real gun in your home, but with a Brocock adapter and barrel sleeve, you can, as it is just an air pistol. It also has *exactly* the same trigger pull, feel and looks as your regular gun.

sibear, yes, that's right. To get a new one legally, you need Section 5. Which is impossible to get. So you can buy (and be "trusted" with) a .50BMG rifle, but not a toy air pistol. Great country!

[hemiboy]

Thanks for the drawings. I made an adapter from good quality steel and fired a few rounds from my "ME Specialist". I'm a happy camper, except about one in six shots where the bullet struck the target sideways. Whats up with that? Too sloppy tolerances on my adapter?

[5_seven]

I found it was easier to purchase a blank shooter and switch out the barrel and cylinder for .22 cal steel. I bought a 'replica' of an old Olympic arms snubby for twenty bucks, the cylinder was about thirty, and I just bored out the barrel, put in a liner, and she fired fine.

My reasons for using a starter pistol are seemingly obvious, it's meant to fire blanks, which are simply cartridges without the bullets (though there may be differences in the powder used, or the amount, if I'm wrong please correct me) so you know it's meant to take that kind of stress.

And since the only kind that you can effectively modify into a live fire weapon is a revolver, it's easier to find one real cheap. The one I purchased I got at a hunting goods store, if they ask any questions, it's so you can train your dog for hunting. I don't know about the availability across the pond though.

[grendel23]

Even if a starter pistol used the same type and amount of powder in a blank (I doubt it), it would generate very little pressure due to the lack of confinement.
I wouldn't assume that such a device would safely fire a live round. I would fire several rounds from cover remotely and check for damage before I would hand fire it.

[tomu]

...snip except about one in six shots where the bullet struck the target sideways. Whats up with that? Too sloppy tolerances on my adapter?

Congrtulation, for making these adapters. I experienced the same problem with my first prototype adapters, the problem was that I drilled the hole through slightly angled because the drill went off maybe 0.1 mm or so. Solution was I drilled the hole first in the round stock and then turned the outside contours between centers.

[5_seven]

Even if a starter pistol used the same type and amount of powder in a blank (I doubt it), it would generate very little pressure due to the lack of confinement.
I wouldn't assume that such a device would safely fire a live round. I would fire several rounds from cover remotely and check for damage before I would hand fire it.

I used a cylinder made for firing live ammunition, and put a liner in the barrel, (as I'd written in my previous post.) I have fired it. It's not accurate, but it works, and it's safe to shoot.

[Arisaka]

Congrtulation, for making these adapters. I experienced the same problem with my first prototype adapters, the problem was that I drilled the hole through slightly angled because the drill went off maybe 0.1 mm or so. Solution was I drilled the hole first in the round stock and then turned the outside contours between centers.

Hello Tomu,

Are these adaptors for sale ?
Great sollution if you live in Europe :cool:

[tomu]

@Arisaka

Unfortunately I can't sell these adapters, under the valid gun laws in my country it's not clear if one needs a licences to buy them. And I'm certainly not the one who will find out in judical trial.

Interesting enough it is not illegal to make them by yourself at least where I live. Who am I to ask for some sense in laws.

If you can't make them yourself, there are always small machineshops who will make them for you for a fee. All they need is a scetch and the exact measurements. Without the hammerpiece it's a hardguess for them what the adapters are for.

[Gunjack]

An alternative for the .22LR cartridge might be the .22WMR that delivers about the same energy on target as a 9mm para. The only trouble is the high chamber pressures.

I know st37 steel (common) can hold the .22LR pressures but what about the .22WMR?

The .22WMR the same in rim and diameter as the .22LR, the only difference is in its length and of course its energy and pressure.

[tomu]

The .22 WMR is simply to long, don't forget you also need the hammer/striker piece.

If pressure would be the only concern just use 42CrMo4 (in the US I think it's 4130) or similar steel.

[Arisaka]

@Arisaka

Unfortunately I can't sell these adapters, under the valid gun laws in my country it's not clear if one needs a licences to buy them. And I'm certainly not the one who will find out in judical trial.

Interesting enough it is not illegal to make them by yourself at least where I live. Who am I to ask for some sense in laws.

If you can't make them yourself, there are always small machineshops who will make them for you for a fee. All they need is a scetch and the exact measurements. Without the hammerpiece it's a hardguess for them what the adapters are for.

I'm to the west of your location if you live in Germany and am very font at al the ersatzteilen :cool: Next month i will be at the Kassel messe and will watch some of these revolvers.

[Cobalt.45]

I know st37 steel (common) can hold the .22LR pressures but what about the .22WMR?

Keep the wall thickness >.25".

[eback83]

please can somebody post some pictures on the adapters ? the old links dont work... =(
thanks

[Boom-stick]

I went down the route of using shot gun primers but found them very dirty. I actually adapted the TAC's internals by using the guts of the TAC to hold the primer instead of making a whole new sleeve. Worked well, but very slow on the re-load. This of course only works on the Brococks with sprung firing pins, my Fox rifle works on a canterlever system and therefore can't deliver the force required to fire the primer.

[onemanriot]

He who didn't have access to a lathe or other facilities could always adapt an existing brocock cartridge to fire 8mm centerfire blanks. This could be done via drilling out the inside so that the blank is a TIGHT fit and filing down the end plug leaving only the thread.

This is possible but difficult using a and drill, as there is only JUST room for the blank. The central rod from the cartridge can be suitably butchered to form a striker.

There is a lucky individual who has access to a supply of obsolete .32 blanks, with the rear plug removed these are a near perfect fit inside the cartridge.

PLEASE NOTE that any such bodging of the brass cartridges while it may work and be very entertaining is not safe. tomu's method is safe however especially if used in one of the wheirauch guns.

[Osis]

Time to wake this thread up...

I bought a brand new Brocock ME38 magnum .22 for a couple of weeks and this is what I've made during christmas. This cartridge is easily loaded with a .22lr shot. I haven't seen any signs of high pressure etc. It really works perfect. Here are som pics of what I'm talking about:

All parts needed
http://img172.imagevenue.com/img.php?image=80039_IMG_0056_122_1077lo.JPG

Simply put things together
http://img106.imagevenue.com/img.php?image=80365_IMG_0057_122_1163lo.JPG

And it's ready for firing
http://img211.imagevenue.com/img.php?image=80368_IMG_0058_122_259lo.JPG
http://img150.imagevenue.com/img.php?image=80371_IMG_0059_122_1067lo.JPG

The firing pin and the empty 22lr cartridge
http://img205.imagevenue.com/img.php?image=80377_IMG_0060_122_111lo.JPG


I also made some drawings with correct measures for you guys to work with. (PDF-file ~6Mb)
http://www.megaupload.com/?d=TI1LMU5S


And of course... ONLY USE IN .22 GUNS!!!

[tomu]

My congratulations Osis this is an ingeniously simple idea much easier to make than mine with much less tools.

Great!

[Boom-stick]

Osis,

Did you make them up yourself or did you get a machine shop to do it for you?
either way, it looks great.

Much better and safer than my shotgun primer method.

[Latindude_002]

Hello, new guy here, I also have a brocock revolver that I'm looking to add kick to. (I'm in the USA, no ban here).

There's a company in the USA that makes cartridges powered by primers, for use in centrefire guns. They also supply a .177 barrel to install in said guns. I am in the process of having some cartridges custom made for a brocock, using the 209 primer. I will report how well they work, although some people who have used 209 primers report 10ft/lb of energy, a 50% increase from air.

Osis, you made a brilliant invention; however, a .22 short bullet is 0.223, as compared to regular airgun pellets which are .220. Does the wider bullet not cause damage to the barrel?

[Boom-stick]

, a .22 short bullet is 0.223, as compared to regular airgun pellets which are .220. Does the wider bullet not cause damage to the barrel?

I'm not osis or connected with him/her but the .22 slugs from rimfire rounds are a pretty soft lead compound, barrel damage is minimal.

[Chris Werb]

Section 1 (Brocock grandfathering) is fairly straightforward, just have the police come round for an interview, send them counter-signed pictures, money, get a safe, go to a gun club for 6 months, fill out a big form, have your criminal and medical records checked, and more.

Section 5 (where non-grandfathered Brococks are) is a letter from the Secretary of State, and allows ownership of real pistols, machineguns, rocket launchers, etc. I've heard that there are 7 people with these for pistols in the entire country. Even gun shops can't have them! Oh, and expanding bullets live there too, along with AP and explosive and incendiary rounds.

Sorry but you can't 'grandfather' Brococks - they're all S.5 - it's just that owners that had them were allowed to declare them by the date Part 5 of the Antisocial Behaviour Act (2003) came into effect and have them put on an FAC (the police could not refuse an FAC for this purpose for lack of 'good reason'). (Other S.5 weapons also go on FAC if you're not an RFD - the dfference is the Chief of Police cannot refuse you an FAC if the Home Secretary has granted you the S.5 authorisation). If you 'discovered' you had a self contained air cartridge system gun (even a lever action rifle or a Saxby & Palmer No4) you would have to hand it in.

Here's the section of the Antisocial Behaviour Act (2003) under which sales and transfers of Brococks were 'banned'.

http://www.opsi.gov.uk/acts/acts2003/ukpga_20030038_en_6#pt5-l1g39

Osis, you made a brilliant invention; however, a .22 short bullet is 0.223, as compared to regular airgun pellets which are .220. Does the wider bullet not cause damage to the barrel?


I thought .22S/L/LR bullets were .221" - hence their inaccuracy in blowback adapters like the M261 for AR15/M16 type rifles chambered for .224" bullets? Strangely enough early .22 Hornets took true .223 bullets (which are still available) although later/current ones are .224.

[Padro]

I found these pictures of a real conversion set for a .38 revolver