.17 armor piercing?

[phyrelord]

I was looking at the .17 HMR round the other day and it hit me that it had a very close resemblance to the round used in the FN P90 and their pistol the FN Five seveN. This round (the belgian one) will penetrate body armor. Does anyone know for sure if the .17 will punch a whole through Kevlar. If it does what would be the best pistol to convert. I have a walther P22 but it's magazine capacity is only like 10. I would like to build something similar, albeit much cheaper, to the P90. The magazines should hold the necked down .22 round without much modification. All this taken into consideration would something like a tec-22 be sufficient. Any ideas on this sort of PDW (New buzzword all the big companies are throwing around)? Also with a tec-22, threads already there for a suppressor :)

[daysleeper]

Yes the round with a FMJ bullet would easily punch through some vest with no problem, so would a 22 magnm round, thing is though. Noboby makes or will make a pointed full metal jacket for either of these for this very reason, all of the .17 bullets are either hollow point or varmit ballistic tips.

But here is a solution for your problem. A .223 armor piecing round is the same diameter as a 22 magnum bullet, and it will fire through a 22 magnum barrel, I know it will because once in my sleep, dreaming I did it. But first i had to cut down the 22 magnum case length and remove some powder so the longer .223 bullet would fit and the whole thing not be so long it would not fit in the 22 magnum magazine.

This test of mine was very informal and quickly put together on a whim, but it worked none the less.

So here is the solution to easy to get pistol Armor piercing rounds, to protect yourself against body armored thugs and crooks, regardless of their employers idenity.

Take a ss109 round from a .223 cartridge, measure the over all length of a new 22 magnum round, then carefully remove the 22 magnum bullet with some pliers, take your time and do not distort the shell to much. Next dump out the powder from the 22 magnum shell, then cut down the shell so that when the new .223 round is installed the over all length is the same as the 22 magnum round un-altered. for proper crimping do a search for " reloading 22 magnum bullets" it was very popular in the 70's and i found the info in 5 minutes. Some powder will have to be remove for the longer bullet also, but don't remove to much, just enough to allow the bullet to seat without compressing the powder to much. Then use the information to properly crimp the new bullet and there you go, armor piercing pistol bullet. After all the research is done and a few prototyps made, one could manufacture these bullets about 100 a day, with very little effort indeed.

But be warned armor piercing pistol ammunition is highly controled, get caught and go to jail, period. So if you are smart only do these things in dream land, where laws don't exist.

In my dream I used a very small tubing cutter to cut down the 22 magnum case, and neddle nose pliers to remove the 22 magnum bullet, BUT be carful man, these things are rim fire, keep any and all stress away from the rim, fortunately the 22 magnum case is very long and plenty of room to work with before getting anywhere near the rim.

Perhaps even a subsonic round could be made, and since the bullet is pointed and heavy, it should cycle the action of most autos, and also pierce the armor of your foe.

Hope this helps with your needs for knowledge.

[NickSG]

I have a bad feeling about this... :(

The .17 HMR is a necked down .22 WMRF, not LR. It will not fit in any .22LR gun nor magazine that fits into a .22LR firearm. The bullet is loaded with a small .17 caliber 17 grain bullet, and with around 5 grains of DBSP, it can easily get its bullet going well over 2500 FPS from a rifle length barrel. From a 8 inch barrel, velocities should be around 2000.

Despite its light weight, it is capable of penitrating level III vest at about 30 feet. However, after defeating the vest it will have the same energy levels as a 16 dollar BB gun.

It has an explosive effect on small animals, but for SD even a .22LR (130 FPS compared to about 250) is better. The .17HMR rarely passes through a milk carton filled with water, although it will blow it up pretty nice. In ballistic gelatin, penitration is about 6 inches.

The .17HMR IMHO is a cartridge you get less than what you pay. Some .22 magnum rounds are capable of spitting 30 grain JHPs at just over 2400 FPS, just shy of what a .17HMR gets with a bullet half its weight.

[john_smith]

Even if you could somehow mod your P22(or any other blowback auto) to acommodate those rounds it will probably blow up the first time you fire it. At very least you will have a ruptured case. There was a 22WMR pistol (Grendall or Grendell) in production a few years ago, though, with a double stack mag and all.

[A-BOMB]

I think Tarus(sp?) is makeing a .17HMR revolver, And if you want a .17HMR semi-auto, get a 70% complete ruger 77/22(I think that is the name of the ruger 10/22s, .22WRM big brother) and get a .17 cal barrel for it and finish up the last 30% of the receiver. The .17HMR is meant to use up all of its energy in the target and not leave the target whole. At the speed the bullet it traveling when it hits a soft flesh target it pretty much explodes make a big hole. If the target is not wareing body armor this cartridge would be good, but thats about it.

[daysleeper]

Yes John Smith, the Gredal had a 30 round magazine!! But the BS AWB put an end to that pistol.
Also the round I was describing being built is quite safe, since Aquilla is going to be producing a subsonic 22 magnum round with a 77 grain bullet, built similar to their SSS round, both require cutting down the case length to accept the bigger bullet. And their ammo is quite safe indeed, so I don't think there would be any blown up guns or ruptured cases, besides cases will rupture in bolt guns just as well as in autos.

[NickSG]

Daysleeper- The problem with your dream is that SS109s bullet weighs 62 grain, compared the the .22 magnums average of 40. A heavier bullet with less powder IMHO wont work. With all the powder, you should be looking at velocities in the 900 FPS range (with a 6 1/2 inch barrel). Take some powder out and you could be as low as 800.

Heritage Arms has just came out with a SAO 6 shot 17HMR revolver. You can expect to pay anywhere from $130 to $200 for this gun. I have their .22LR/.22 mag combo, but not the .17HMR.

Like I said earlier, .22 magnum rounds are capable of pushing a 30 grain bullet over 2400 FPS, so switching to a bullet nearly half its weight is just as waste of energy. Also, some companies do manufacter FMJ bullets for .22 magnum, but like ABOMB said, dont hold your breath for a FMJ in .17HMR.

[daysleeper]

So then you would have a very simple to construct, sub sonic round that would facilitate silencer use
for the discreet operator? Where is the negative side? Also most FACTORY made subsonic 223 bullets only travel at 950 fps
so then you can duplicate that performance for one tenth the cost for EBR susonic 223 bullets, which do not even cycle the action on autos like the AR15.

The only real downside to my idea is that a barrel with a faster twist is required for any type of accuracy past 20 yards with the ss109 round, 1 twist in 9 inches is the minimum twist rate. These barrels are already available for the ruger 10/22 magnum and the 10/77/ ruger 22 magnum models.

Your thoughts?

[daysleeper]

My last post did not make it for some reason, so I'm gonna try this again.
NickSG the EBR factory made 223 subsonic bullet for the AR15 weapons only goes 950 fps, so what is you point?
And it will still penetrate lower level armor and is accurate.
22magnum full metal jacket bullets have rounded noses, thus rendering it not armor piercing.

The only downside to my idea is the need for a barrel with a minimum of 1 twist in 9 inches, but they are already made for several 22 magnum models.

[NickSG]

Even though the FMJ .22mag rounds are RN, they still have the velocity to defeat most armor (out of a rifle barrel of course). Velocity has more to do with whether or not a bullet will defeat armor than bullet construction. Chances are a RLN bullet at 2500 FPS will penitrate a level II or higher vest. Pretty much anything faster than 2300 FPS will defeat armor.

The subsonic AR-15 ammo is already slow from a rifle barrel, but from a pistol, it could be 25-50 percent slower.

Edit: Is it just me or is E&W acting weird today?

[CommonScientist]

Whsat if you customized a .30 shell so a .17 could fit in it? It would be a hell of a neck down but it should give you massive velocity. NickSG, Yeah it is , either they arnt accepting my posts or it forgot about me :(. It gets annoying though because i dont know if they are delayed and i dont want to double post. But this isnt the forum or the topic to be talking abuot this in.

[Jacks Complete]

I have it on good authority that the SS109 is the only .223 round that will defeat the UK Army body armour, plates and all. In my thread "Stopping the bullet", I showed how the penetration of the .223 rounds had increased over time.

As for the PDW, from HK, it is quite a nice toy. I have handled it, and it is an awful pistol, but then it changes to a nice submachinegun in seconds. The red dot sight is nice, too. As for the effect, the bullet is 4.6mm in diameter (that is .17-ish, .181 in fact), and does 3200+ fps, depending on bullet weight. I have seen a board made of 2mm titanium armour, with 13 layers of Kevlar weave behind it, which was shot from 10 yards to 200 yards, with bullets made from copper, brass, tungsten, steel, steel coated with Teflon, and various others. It had various exit holes, and a lot of rounds stuck halfway through.

The bullets are so small that they are made in a totally new way. A feeder chuck and a CAM lathe simply machine them out of solid bar stock. Hence the range of materials. (Normally, bullets are either cast or pressed and/or swaged). I actually have a copy of the HK product sales leaflet for it, somewhere...

So yes, a tiny bullet, going very fast, made from dense, or at least hard, materials, will zip through a vest. Up to 200 meters was the design spec. I believe it passed. The whole thing was only a 7" barrel, iirc. I will dig up the sales sheet if anyone wants to see it. http://world.guns.ru/smg/smg49-e.htm will tell you more.

[phyrelord]

jacks complete that was what i was going for also when several bullets are fired at a target, as in a full auto, will also destroy the characteristics of kevlar. So a three round burst with a small, fast moving round would surely do damage to anyone in a vest. Another question how hard would it be to convert a standard 9MM into a double mag 22 or if it's possible to find a round about the same size as the .22 hornet, which is a round that most old timers swear by but i haven't seen anything really more impressive than a 22 mag. Ultimately what would be the best way to make a small highly lethal small caliber pdw out of say a pistol. I would like to try something like the Five Seven from FN. Also does anyone know where i could find a file on ballistics and other info on various rounds? i used to have one but my computer crashed.

[A-BOMB]

I was able to shoot a Five-Seven, at a product demo shoot a few years ago while I still worked as my local departments weapons teck, some company had set my a shoot for some local departments and there were some agents from one of the 3 letter alphabet gangs. I can't remember which company had set it up, I don't think it FN. Well, I liked the 5.75mm rounds contolablity and recoil and the magizine capacity or the five-seven, but I just could not get my head around the polymers and plastics the gun is made of, I know that a Glock is made of similar think and I know they are good pistols, But I still like the feel of metal and wood in my hand, If I was still the departments armor and they made a F92 in 5.75cal I'd get one. I'm still mad that they fired me, It wasn't my fault that my predecessor hadn't cleared the chamber of this old colt1903, he had left a live round in the chamber, I picked it up and pointed it at my computer which had froze on me again and bang, I lost my job :mad: , If that old bitch cade wasn't already dead, I would of killed him. Well I can't cry over spilled milk.

[daysleeper]

Here is an idea, what if you took a standard pistol round, just the bullet, and drilled out the base, and inserted steel or tungsten rods, then just reload the bullet as normal, if it would work then any decent pistol could make a fine pdw, if recoil is not a deterant.

One note though, I've been shot several times while wearing a vest. When I was much younger and dumber, I let a friend of mine shoot me 3 times with a Ruger MK2 at point blank range using high velocity rounds, and none penetrated, obviously. I also let him shoot me with a 32 acp at point blank. The point is that, they all hurt like fucking hell. I would imagine that if you shot a foe wearing armor with say a .45 acp, it would disable him/her regardless if it went through.

And if it was a heart shot, would stop his heart or cause enough internal damage to kill him.

[Third_Rail]

Personally, if I were to attempt such an illegal feat, I'd ude penetrators from cut-open surplus 30-06 AP rounds; they're hard steel, pointed and boattailed. They would fit nicely in a .357 -.45 round, drilled out first for the penetrator, then having molten lead poured over the back of the hole where the penetrator was inserted. Of course, this is very illegal, so don't do it; I didn't.

[NickSG]

A 7.62x39 AP round reloaded into a 7.62x25 (which is chambered in a few pistols) would be pretty effective. They two arent the same size, so you would have to make adjustments.

The problem with reloading unfired cases is that the cases are still crimped. This means that it would be nearly impossible to fit a bullet of the same size in. CCI sells accessories for reloading rimfire ammuntion. I suggest you guys do that. I used to, and since the .22 magnum and .22LR bullets are the same diameter, I came up with some petty darn hot .22LR rounds. :) A 32 grain Stinger HP was chronyed at close to 1450 FPS from a 6 1/2 inch barrel. Factory ammo cant compare. ;)

[Third_Rail]

Are there any current production 7.62x25mm pistols? I thought that they haven't been made for ~50 years...

[NickSG]

They are pretty rare but if you keep your eye open you might see one at a gun show every once in a while. I never bought one though, becuase becuase they are usually priced pretty high, and I dont have any reasons for any guns with AP capabilities.

You do know that im HMC dont you?

[PHAID]

They are not that expensive and if you get a copy of shotgun news you will find several places that sell them.

[Third_Rail]

Alright then, but no current productions? Figures.... Oh well, an old Tokarev for me; and no, I didn't realize that you're HMC; how are you?

[NickSG]

Im doing just fine. :p

I would take PHAIDs advice. Most gun shows (around here at least) are overpriced. You should be able to find a better deal online, but it requires S&H and they have to ship to a FFL dealer.

[Third_Rail]

C&R, my friend, C&R.... I'm actually going to go for a couple of CZ-52s and a bunch of extra parts (especially new production firing pins) for ~$250.

[charger]

Would it be possible to turn your own bullets for the .17 the same way Jack's Complete said H&K does? Brass would probably be ideal because of its ease of machining and its ballistic properties (later versions of KTW were made of brass http://www.guncite.com/gun_control_gcgvcopk.html) if you have your own lathe I don't think it would be overly difficult, but there are probably problems that someone might know about.

[xyz]

Just like it says in that file, the brass causes a lot of barrel wear. I am sure that a pure copper bullet would be just as easy to machine and you shouldn't have any trouble getting it to pierce body armour if you are firing it from a .17 because of the velocity.

I have attached an image that I am sure you will all be interested in, a pure copper conical bullet outperformed the KTW. The bullets, manufactured by a company called Arcane, are very lightweight and fast with the .45ACP version doing 1600FPS. Best of all, the Arcane bullets look extremely easy to duplicate on a lathe.

[Jacks Complete]

An easy way around that problem would be to take the brass rod, and coat it with something. You could electroplate copper onto it, or perhaps dip it into molten lead or zinc or something.

I am sure one of the chemists/metallurgists on the board will know a good way to deposit a few fractions of a millimeter of something a bit softer onto the rod.

You could also coat it with something like MolyCoat, or any other bullet coating.

[xyz]

A lightweight conical bullet made from hardened steel and then given a copper electroplating should work nicely. It would however take a long time to get enough copper onto the bullet though and you would have problems making sure the jacket was the right thickness. You could plate too much on and then machine it back to the desired dimensions on a lathe.

I also had the idea of (I'll use the 9mm as an example here) taking an 8mm steel rod, hardening it, then somehow securing it (epoxy?) inside a 9mm OD copper tube with 0.5mm walls.
Of course, the dimensions may have to be changed slightly to give the epoxy (or whatever) a small space to fill so that it works properly. The copper jacketed steel rod would then be cut into small pieces (the length of the bullets) and turned down to a point on a lathe.

The above is entirely theoretical and there are probably flaws with it such as epoxy not being strong enough (I mentioned epoxy because the glaser safety slug holds together OK and it uses a modified epoxy) and the rod being difficult to machine because of it being made of two metals of vastly different hardness.

[Chemical_burn]

You could also give a steel conical bullet a lead jacket just mill the round to about .5mm under the bore and them dip it into lead to build up a jacket on it and them remill to correct bore.

I think this would be far easier to do this than copper electroplating.

[xyz]

A lead jacket will limit your velocity to about 1400fps, you want more than that if you are trying to pierce armour. A lead jacket will also cause barrel fouling and need frequent barrel cleaning, especially at higher velocities.

I doubt that any lead would even stick to the steel if it was immersed in molten lead and then pulled out.

[john_smith]

@xyz: the rod had to be secured VERY well or it may be pushed out of the tube leaving the latter halfway down the barrel, and on next shot...ka-fucking-boom! Maybe threading the rod and tube might work...

[xyz]

Threading it is a very good idea, I would coat the steel rod in loctite before it was screwed into the copper tube, otherwise it may loosen during machining.

I doubt that the gun would explode if the jacket did stay in the barrel (well, so long as it wasn't a cheapo POS gun. I have heard of a mauser being fired underwater and holding together fine despite the fact that it was pushing 3 times it's normal projectile weight due to the weight of the water in the barrel) but it would be best to avoid the possibility anyway.

[charger]

Would the copper tubing be thick enough to accept threading? If it is, then the steel rod would have to be so small it might not be effective. To keep a decent core diameter, pressing a steel rod into an undersixed tube might work better. or heat the tube so it expands and then insert the steel rod. The copper will contract very tightly over the rod and should hold.

[powdermunkey]

Naah- the way to do it is to use steel rod and a swaging press to swage on a copper jacket. Or do like I do- load discarding sabot rounds. An SS109 AP in .224 caliber fits into a stock polymer sabot. I load them for my CZ-52, which is the 7.62X25 discussed earlier. The muzzle velocity out of a CZ-52 is pretty decent, although they are not the most accurate rounds, and they don't feed all that reliably because of the pointed tip and the polymer sabot's exposed shoulder. If you really NEED to penetrate body armor, use a rifle. My FAL wil shoot through 1/2 inch mild steel, with surplus FMJ ammo.

[xyz]

About the threading, I would use the finest thread possible to minimise the thickness that the jacket needed to be, then just use the thinnest jacket possible that will still accept the threading. It should still be possible to get a 6 or 7mm steel core into a 9mm projectile.

If you were going to heat the jacket tube to expand it you would have to make sure it was heated totally evenly or it would warp. Warping would happen very easily because it is made of thin metal.

[TreverSlyFox]

For the US members,

aimsurplus.com has CZ-52 pistols with holster and 2- 8rnd mags for $99.95

also 1,250 rnds of Romanian 7.62x25 for $109.95 due in the 1st of Feburary.

The 7.62x25 is a legendary "Vest" killer and anything less than a Level IIIA with a Titanium rifle plate is dead meat to this round. Remember the "plate" only covers the center of the chest area so shoot a little low just in case. The plate is only about 8" x 8".

Why re-invent the wheel when there is a perfectly good (and cheap) weapon and ammo to be had. Why gang-bangers haven't figured this out is beyond me, if they ever do there isn't a patrol cop that would be safe in the US. Most cops wear Level IIA vests because they'er more comfortable, only the departments that issue IIIAs and demand their use would be a little safer but that's like 1 in 5.

When I was on the department I wore a Second Chance "Monarch" Level IIA with Titanium plate rated for a .357 mag with a 158gr HP at 1400 fps. I only knew 2 Officers that wore a Level IIIA with a plate and they bitched all the time about them.

[phyrelord]

I recently like this weekend purchased a cz-52 and i'm fucking impressed. The round has balls, i shot at a target about 75-85 yards away and hit it, it was the size of a gallon milk jug. I also shot into an engine block after shooting through all sides of the car, the bullet actually went through! not all the way but neither will a .308 (shooting from the side of the car so it would have to travel through 4 cylinder walls.) Thanks i'm pretty sure i could turn out some copper Arcane bullets they look really simple and you can find copper rods at any hardware store, plus the 7.62 looks really easy to reload plus add a little extra powder, and voila. big bad hand gun. Another thing i noticed i shot like 10 mags through it and it never once jammed. On dissassembly i noticed that it uses an operation similar to the mp5 and g3, very bad ass, thanks for the help.

[blacktalon]

phyrelord

Must have been an aluminum block... 7.62x25 gets pretty good penetration but not on a steel block. Lol. A 9 will go through the cylinder wall of a aluminum 4-banger though. If you want the mack daddy of penetration, they make sabots for 7.62x25 that let you fire 55 or 60 grain .223. Hotload yourself some steel core green tip and you could blow holes through both sides of a vest and the 12" of ballistic gelitin between them. :D

[Dave the Rave]

The idea of swaging a plain steel core on copper jacket it´s the most economic and quickly way to do, but the shoot will be too ligth, with no inertial energy to disable the target. Maybe lathing the bullet outside and then drilling a hole inside to swage with lead will be the best thing to do, and then, paint the outside with a coating of teflon.

At my Country we can purchase liquid teflon at any chemical company, and it can be aplied with an air brush and cooked at an residential oven. It cooks at 300C, and it´s fairly achieved by my oven.

The teflon coating will act like the coper jacket, giving something to the rifling to grip, and will help to mantain the bore clean and smooth, and the lead will add weigth to the bullet.

Or we can just make an alloy of lead and tin, cast the core of the bullet with it and swage it on the coper jacket. I´ve made some tests and this alloy can be as heavy as the plain lead and as hard as some steels. It can´t be bended or cut or even smashed without some hard efforts.

[Jacks Complete]

Personally I would go for a moly coat on the bullets. A lot of target rifle people use them, and it reduces the wear on the barrel, as well as the pressure spike when firing. Check out a gun shop and ask, they will sell you the stuff. Failing that, you could try a car shop, as some people like to coat the moving parts with it, apparently.

It is basically just molybdenum disulfide powder, which is tumbled on to the bullets before loading the round.

http://mywebpages.comcast.net/jesse99/moly.html - A simple home method

[john_smith]

Steel isn't THAT light, and steel core/copper jacket bullets have been around for a long time. IIRC KTW bullets were steel and copper with teflon coating, and THV's are mostly aluminium(?!) and actually alot lighter than most other bullets of same calibre.
Btw the reason why an empty jacket lodged into barrel will blow up the gun is not increased projectile weight, but rather projectile diameter - the second bullet will act like a wedge and lock the combo firmly in place. A friend of a friend of a friend blew up a bolt gun (don't know the exact model or calibre) with "homemade softpoints", aka FMJ's with tips filed off.

[Dave the Rave]

Yes John S, but it is very ligther than full lead bullets. The ligther the bullet, the less inertial energy it can store, and less inertia means less penetration.

If you use an hard, yet heavy metal, like tungstein or some lead alloy, you can achieve more precision, penetration and distance on your shoot, on the other hand, one bullet cast out of aluminium or brass/copper, will not achieve higher veloties, exactly because it can´t store as much energy as can the heavy ammo.

Home made soft points aren´t so dangerous, I´ve made some out of 9mm, 7,62, .38 and even .45. None of it has done any harm, and probably what hapens to you friend was done by an inappropriated swagged bullet, with the jacket loose or by an factory bullet filed down too much, wich tends to spit out the lead, leaving one empty jacket down the barrel.

With electroliticaly jacketed bullets, it won´t happens, cause the electrical bound are stronger.

Molybdenium can be much better than teflon, it is cheaper, easier to work with and as non adherent as teflon. The best part about it is that it will not raise suspects as does teflon and can be reached through any automotive parts store.

[NickSG]

Dave- You sort of have it backwards. Light, fast, bullets penitrate armor better than slower, heavy bullets. Its the opposite, however, in flesh. The heavy, slower, bullets penitrate deeper than the light, fast bullets.

The higher velocity lightweight bullets also have more energy than the heavy, lower velocites bullets. The lighter bullets also have higher velocity for a certain distance, but the heavier bullets tend to have higher velocities and more energy at long distances.

[Blackhawk]

The impact energy of bullets can go either way. Obviously the best combination would be a heavy bullet travelling very fast, however you are unlikely to get this in small callibers. A light bullet travelling fast can deliver as much, more or less energy than a heavy bullet travelling slowly depending on the values of speed and weight. Damage to targets is another thing altogether. A soft target is generally effected much more by a slower blunt round than it would be by a fast armour piercing round, this is because the slower round is more likely to break up and become unstable and tumble as it travels through a viscous material. Once you get to something like the 11.5" long shell from an 'avenger' style cannon though either way you are red mist :D

"heavier bullets tend to have higher velocities and more energy at long distances"
This would be true if the heavier bullet was the same calliber than the light bullet and fired from the same shell as the light bullet would have less momentum with which to overcome drag. However a heavier bullet will have a higher inertia to overcome so a similar powder load to a light round would give similar energy results (with the heavier bullet slower with more momentum compared to the lighter bullet).

[Jacks Complete]

"heavier bullets tend to have higher velocities and more energy at long distances"
This would be true if the heavier bullet was the same calliber than the light bullet and fired from the same shell as the light bullet would have less momentum with which to overcome drag. However a heavier bullet will have a higher inertia to overcome so a similar powder load to a light round would give similar energy results (with the heavier bullet slower with more momentum compared to the lighter bullet).

Hold on, that makes little sense. Yes, the heavier bullet is slower to speed up, but it is then slower to slow down. The momentum they have, at the muzzle, from the same powder charge, will be the same. By this, I mean that the speed of the bullet will be proportional to the mass (inertia), and so the sum, the momentum, will be very much the same. (I=mv) This DOES NOT mean they have the same Muzzle Energy, as kinetic energy goes up as the square of the velocity (KE=0.5*m*v^2).

Let me try to make this clear, and stop any confusion:

A light bullet, fired at the same velocity, in the same calibre (or, more basically, the same cross sectional area) as a heavy bullet, with lose more energy per unit distance travelled through the air. The muzzle velocity will drop off faster. It will also be affected more by crosswinds.

A heavier bullet is almost always preferable, due to a higher resistance to being pushed off point of aim by crosswind, and having a higher KE when it arrives.

The flip-side to this, is that a bullet that is lighter will speed up faster when fired from a gun. This means a higher initial velocity may be obtained for a given powder charge, without dangerous breach pressures or excessive recoil.

There is a limit to how fast a bullet can be pushed, regardless of weight. This is due to the rate of expansion of the gases at reasonable pressures and temperatures.

Also, lighter bullets need to be spun less fast, with a longer twist on the rifleing, to be fully stabilised (rather than over-stabilised, which leads to jacket separation, excessive wear on the rifleing, wasted energy in the rotation of the bullet and very weird over-penetration in soft materials as the bullet won't tumble, as well as lead bullets fraggin themselves due to centripetal forces). Under-stabilisation results in keyholing, poor grouping and bullets tumbling before they ever reach the target. Since it is not possible to change the rifleing on a given barrel, your gun will have a specific range of bullet weights and velocities available to it, and you, for anything approaching accuracy.

Obviously, when using just one material, such as lead, the weight of the bullet head is determined solely by the length of the bullet, as the calibre is fixed by the rifle.

For something like a .17"/4.5mm you are going to cut just the one barrel, and I suspect that you will want to settle on the right bullet mass in the preferred materials, before you cut your barrel rifleing. You can go for a long steel bullet to make up the mass, but the sectional density is sometimes an issue.

http://home.snafu.de/l.moeller/military_bullet_wound_patterns.html gives an interesting insight into the various performances of different NATO and Soviet Bloc ammo.

[nbk2000]

I'm still mad that they fired me, It wasn't my fault that my predecessor hadn't cleared the chamber of this old colt1903, he had left a live round in the chamber, I picked it up and pointed it at my computer which had froze on me again and bang, I lost my job. :mad:


How many of the four gun safety laws were violated?

1. All guns are always loaded (until you establish whether they are or not). If you think it is unloaded, check it again. Remember to check the chamber as well as the magazine. A semi-automatic gun will load a cartridge into the chamber when the
slide is pulled back, then released. Remove the magazine, then pull back the slide to eject the cartridge in the chamber.

2. Never let the muzzle cover anything you are not willing to destroy. Keep your gun pointed in a safe direction at all times: on the range, at home, loading, or unloading. Don't point guns at people or animals except when necessary for self-defense or hunting.

3. Keep your finger off the trigger until your sights are on the target (and you are ready to shoot). You may pull the trigger by reflex if you stumble while your finger is on the trigger.

4. Be sure of your target. Know what it is, what is in line with it and what is behind it. Never shoot at anything that you haven't positively identified. Remember that a handgun bullet can travel one mile and a rifle bullet can travel several miles. Bullets
fired into the air will come back down.

You were rightfully fired for negligence in your duty.

[A-BOMB]

For all intents and purposes that gun should have been unloaded we weren't even allowed to keep live ammo in that room and the gun did have its check tag attached (a orange zip tie with the catalog number that we would put through the trigger gaurd and around the slide to signify that gun had a snap-cap in the chamber and had been checked in and before being put in the storage rack)

[Jacks Complete]

A-BOMB,

that just shows why rule one *IS* rule one!

At least you will not make that mistake again in this lifetime. :rolleyes: