Expanding Full Metal Jacket Ammo

[hminsky]

http://www.defensetech.org/archives/cat_ammo_and_munitions.html

Interesting article about a form of full metal jacket expanding ammo

One Answer to Hollow-Tip Bans

pistol-shoot-web.jpg

Defense Tech infrequent contributor and resident ballistics expert David Woroner busted out an interesting first-person analysis of a bullet that could answer soldiers’ call for more stopping power.

As our readers might remember, we reported two weeks ago that a Center for Naval Analyses study obtained by DT found of all the suggested improvements for America’s standard-issued sidearm and carbine, soldiers surveyed said they want a more deadly weapon or round.

CNA pointed out that one answer is off the table: hollow point ammo.

But Woroner took a first-hand look at a type of round that could answer a politics vs. lethality dilemma…

From Dave (it’s a longish entry, but I think you’ll find it worth the read):

Known as the Federal EFMJ for “expanding full metal jacket” the round would appear to be a gift from above to the soldier on the ground. It is fully jacketed, yet expands like a hollow point upon impact.

The basic concept was developed by projectile whiz Tom Burzynski and Larry Head, lead ammo designer for Federal applied some of his magic to bring this bullet to fruition.

So what makes this round so different and special?

Well first of all it is a “full metal jacketed bullet” - this means there is no “cup” at the front as with most hollow points. Standard hollow points work by taking advantage of fluid dynamics - the fluid being the liquid or blood in a target.

While stopping many a fight and still not a bad choice at all, I personally have seen many hollow points “stay intact” - or not expand. The culprit for this has usually been, believe it or not, clothing. When the “cup” or hollow of the bullet is passing through clothing, especially winter type clothing the hollow point can end up filled as it cuts through the material thus preventing expansion.

What’s also pretty cool about the EFMJ bullet is that because it’s fully jacketed, it feeds flawlessly. Anyone who’s spent some time shooting hollow-point ammo has experienced the hollow “lip” catching on the feed ramp of the weapon – forcing an operator to execute “stoppage drills” in the middle of a gunfight.

Besides overcoming the feeding issue, the EFMJ works unlike a typical hollow point on impact. Think for a minute about firing at a target through drywall with a standard hollow point? Nine times out of ten the hollow point will fill up with the powdery drywall.

EFMJ-web.jpg

Now enter the EFMJ. It works by having a piece of encased lead with a tiny nylon/rubber plug. When it strikes its target, it cannot fill up at the front since it’s encased. Instead, it begins to (for lack of a better word) “smush up” the entire round. How it begins its expansion so diametrically opposed to a standard hollow point and its reliance on fluid hydraulics is that the EFMJ operates solely on impact/kinetic input to the front of the bullet.

Part of the manufacturing process of the EFMJ includes creating “cuts” or striations on the inside of the encasing copper. When the bullet impacts, it begins its expansion by impact/blunt force with the “cuts” splitting and allowing the rubber component to continue to flatten. By then it would have entered its target.

Another test I did was to shoot it through plies of standard drywall and it worked great. It penetrated, started its deformation as well. So when it struck the target behind the wall, the bullet was still full of energy, yet almost fully expanded.

Shooting through two pieces of drywall yielded the same result, except it was obvious there was a slight drop off in connecting kinetic energy. You want to be able to shoot through drywall and plywood and still hit something, but you don’t want it going down the block and kill granny sitting out knitting on her front porch.

The penetration I got was very consistent with current kinetic impact understanding and that gave me even more reason to trust this round. To put it quite simply it is harder to shoot through a piece of glass then it is drywall because the glass is more molecularly compact than the drywall.

So when I shot 9mm and 45cal. rounds through each, I was pleasantly surprised to find that although the rounds did penetrate the glass, the expanded as advertised. Having my caliper in back pocket told me that the 9mm expanded to .51 inches and the 45 cal. to .64 inches (all rounds being caught by foam and soft rubber) those numbers are an average for multiple shots on glass. The 9mm in my opinion in straight up head to head performance came out ahead of the .45, I’m sure only because of the higher velocity of the 9mm round.

On the drywall, I found more expansion but not by much, 9mm to .58 and the .45cal to .67 which for either surface, and the energy carried still after impact was surely enough to penetrate a solid 9-10 inches.

It would be super to see our troops carrying the EFMJ in their Beretta, Colt, Kimber, etc. The next thing Federal needs to do is create the same technology in the 5.56 (.223) round, I would be very interested to see the results of that test.

-- David Woroner

 

[Weerd Beard]

http://www.theboxotruth.com/docs/bot10_2.htm

and the stuff works fairly well. Also it will feed well in a gun designed for only RN bullets.

 

[Major D Ret.]

Geneva and Hague Conventions prohibit bullets that
cause unnecessary damage or suffering the theory being
if someone is hit by a bullet no matter the extent of the
damage, his effectiveness as a combatant is so diminished
as to render him combat ineffective - at least for the present.

Using a tricked out bullet to mash more meat is a definite
war crime, or will be construed as one by whomever gets shot
and that will lead to all sorts of bad craziness - like summary trials and executions of American GI's captured while possessing the super
bullets.

Furthermore, this lets the genie out of the bottle, and the
rules get flushed. This means WE will soon be on the receiving
end of soft point and hollow point bullets and may the best
man win. (He will be us, of course, because God is on our side!)

If increased lethality for military rifles and pistols is the goal, get a bigger gun with a bigger, faster bullet, or learn to shoot what you've already got more accurately and keep firing until the target stops twitching.


FACTOID: U.S. Snipers currently use hollowpoint target bullets
to engage enemy personnel. However, extensive testing has proven
these bullets do not expand in soft tissue so their use is NOT a
violation of the laws of land warfare. No harm,no foul.

MAJOR D

 

[Mass-diver]

The terrorist don't play the rule anyways, so if we start using Hps I doubt it will change their practice, plus most of those guys are using 10-20year surplus ammo anyways.

I think it's crazy that our guys don't use HPs in their pistols.

 

[Weerd Beard]

Geneva and Hague Conventions prohibit bullets that
cause unnecessary damage or suffering the theory being
if someone is hit by a bullet no matter the extent of the
damage, his effectiveness as a combatant is so diminished
as to render him combat ineffective - at least for the present.

Try explaining that to a GI who was wounded by an enemy that he shot, and went down....then recovered and returned fire!

We call it stopping power for a reason, and everybody who knows stopping power talks about quality expanding ammo.

Untill somthing is stopped, its still a threat, and I feel sorry for anybody pinned down by foolish rules that say otherwise.

 

[rscalzo]

Federal's line of EFMJ has been out for years. It's nothing new. It is only available in pistol calibers. I use it when I return back to NJ due to the HP ban. I don't see it making it's way into rifle calibers.

 

[Weerd Beard]

Federal's line of EFMJ has been out for years. It's nothing new. It is only available in pistol calibers. I use it when I return back to NJ due to the HP ban. I don't see it making it's way into rifle calibers.

I don't think there's really much talk for it TO be for rifles. More as a replacement for a lousy military ball 9X19 used in the M9.

For rifle, I'd say just going back to 7.62X51mm would fix all ills

 

[Jose]

I agree with the Major. This will be a non-starter due to the laws of land warfare.

 

[rscalzo]

The only reason I see the article leaning towards rifle ammo is the fact the author brings up the military's sniper round using Sierra's 168 Matchking round. A friend who used that round in the Marines told me a while back the JAG lawyers went back and forth for some time before they agreed the round was not to be considered a HP round.

Although it might be a challenge to get that ammo to function reliably in a full auto weapon.

 

[Jose]

The simple reason that the military's M118LR cartridge (which uses the 175 gr Sierra Match King) is land warfare-legal is because the hollow point on the bullet is there only as by product of the manufacturing process for match-grade bullets and not as a purposely designed and manufactured feature to enhance the bullet's expansion.