Evolution of the M855A1 Enhanced Performance Round

[Talyn]

In post-combat surveys and field reports from Iraq and Afghanistan, most Soldiers have indicated that the M855 round works fine, delivering the desired effects against threat targets. But some Soldiers have reported that the round did not perform consistently, causing concern in the ammunition community.

The Army's solution is the new M855A1 Enhanced Performance Round (EPR).

Evolution of the M855A1 Enhanced Performance Round

Perhaps no subject is closer to the hearts of Soldiers than their weapons and ammunition. For decades, this intense interest in

www.army.mil

Army begins shipping improved 5.56mm cartridge

The Army announced Wednesday it has begun shipping its new 5.56mm cartridge, the M855A1 Enhanced Performance Round, to support warfighters in Afghanistan.

www.army.mil

 

[TEXASforLIFE]

"Also notable is the EPR's excellent performance against softer intermediate barriers such as car doors, windshields, or Kevlar fabric. The thinner metal found on car doors poses no problem. When engaging targets behind windshields with the EPR, ARL has shown an increase in the probability of hitting the occupant, due to both the steel penetrator and the copper slug remaining intact through the glass."

kinda funny why this is stated (above quote from the article) as every fmj (no steel tip) i've shot into a vehicle went thru 1 door and out the other thanks to it being a HIGH VELOCITY round. i've even shot hp's that went completely thru a windshield and out the trunk on a 4 door vehicle. even hp pistol rounds went thru both doors. granted it was from a 44mag doing so.

 

[ECS686]

Skimming through one of the articles I didn’t see this mentioned just typical “it’s improved performance” fluff Military and GOV agencies do. Supposedly the main reason the m855 a1 was adopted was environmental impact the Military is going through as it’s a lead free round

From one of the more knowledgeable folks on YouTube!

 

[Cedric]

Interesting articles. One thing I didn't see mentioned was the wound ballistics against soft targets of the improved round. I've mentioned COL Martin Fackler's wound ballistics work before, and he said the 5.56 round had excellent test results in both temporary tissue stretch and permanent tissue cavitation largely because of fragmentation inside the target. I wonder how the M855A1 would do in this regard.

P.S. The article said the US Army adopted the M16 in 1967, but 1-7 Cav had M16s when they landed at LZ X-Ray in November of 1965.

 

[Talyn]

Both the M855 and M855A1 created their soft tissue damage more due to yaw vs. fragmentation which was/is a tendency of the M193.

Once the velocity of both M855 and M855A1 dropped below a certain point they tended to just drill a hole.

The troopers found that out in the sandbox events since the M4's inherently had less velocity than the 20" A2/A4s.

The 5.56 round was designed for optimal performance in a 20" barrel.

 

[TEXASforLIFE]

when they removed the lead and replaced it with copper the need for more steel was inherent to keep it the same length as copper isn't as dense as lead. same shape means same poi and flight w/o changing optic info. flash suppressant was good addition to the powder.

 

[Cedric]

Both the M855 and M855A1 created their soft tissue damage more due to yaw vs. fragmentation which was/is a tendency of the M193.

Once the velocity of both M855 and M855A1 dropped below a certain point they tended to just drill a hole.

The troopers found that out in the sandbox events since the M4's inherently had less velocity than the 20" A2/A4s.

The 5.56 round was designed for optimal performance in a 20" barrel.

Make sure I'm understanding you that the M193 tended to fragment, is that right?

 

[Talyn]

Make sure I'm understanding you that the M193 tended to fragment, is that right?

Yes, it was made to fragment & yaw around.

The M885 was made to penetrate what was thought to be the capability of personal Warsaw Pact armor, and primarily yaw in soft tissue at a certain limit. And the M885A1 was made to be a lead-free version.

The article that I posted explains things pretty well.

I only use M885 (note- I've never seen M885A1 released to the public as surplus or from an over-production run) as a mix load-out alternating with a hot commercial 62 gr. expanding load for Zombie self-defense. For training I use M193 which also works for self-defense.

My .02

 

[USMC6094]

From some talking I've done with guys who've used the A1 round, it's very hard on the feed ramps of the barrel which over time wears the barrel extension out.
Personally, I've never seen a single round of it.
I'm pretty partial to plain old M855

 

[Shibadog]

Both the M855 and M855A1 created their soft tissue damage more due to yaw vs. fragmentation which was/is a tendency of the M193.

Once the velocity of both M855 and M855A1 dropped below a certain point they tended to just drill a hole.

The troopers found that out in the sandbox events since the M4's inherently had less velocity than the 20" A2/A4s.

The 5.56 round was designed for optimal performance in a 20" barrel.

Also, as originally configured, the M16 utilized a pretty slow rate of twist, (1/14”? )resulting in a minimumly stabilized projectile. When striking the target the bullet was upset and would yaw significantly resulting in a wound channel way out of proportion to the size of the projectile. This design feature precluded effectiveness against hard targets esp at extended range. Thus we went to overstabilized slugs which penetrated but with minimal yaw and a corresponding decrease in lethality against soft targets. The military seems to have finally realized that you simple cant beat physics, hence return to a much more powerful round.

 

[Talyn]

The original 1:14" twist round was the M193 which has no relation to this new round and the performance experiences that the US discovered in Afghanistan & Iraq since the standard round then was the M855 which replaced the M193 in the 80's.

Also, why is everything underlined?

 

[Shibadog]

The original 1:14" twist round was the M193 which has no relation to this new round and the performance experiences that the US discovered in Afghanistan & Iraq since the standard round then was the M855 which replaced the M193 in the 80's.

Also, why is everything underlined?

‘Cause my old computer got it “on” and wouldn’t turn it off. Understand the difference between the M193 and the M855.

 

[Talyn]

More...

The M855A1

Signed armorers manual. Price includes shipping.

smallarmssolutions.com

Shown above is a comparison of the M855, M856 Tracer, early M855A1 and the issue M855A1. The difference between the early and issue M855A1 projectile is the plug under the penetrator.

Looking at the cross sections you are able to see that both projectiles are made up of three components. The M855 (left) consists of a copper jacket, steel penetrator core and lead plug. The M855A1 (right) is manufactured from a copper jacket, steel arrow head core with a copper plug. The M855A1 projectile fit the Army requirement for a "green" projectile that does not have any lead.

 

[jschmidt]

So why does the military need a whole new rifle and round?

 

[ECS686]

So why does the military need a whole new rifle and round?

The 855A1 came about to be more “environmental “ friendly more than any “lethality “ improvement

Just 3 or the four branches didn’t buy into it.

We had several issues come up with our M16A2’s in the late 90’s with standard 855. The problem was our leadership decided to shoot 25,000 rounds in one day to get rid of ammo that we had for a while. We are talking around 25 troops we had I don’t know how many guns go down. No matter the round you will have increased issues when you fire that much in a short time.

So while the article is good and the ammo is somewhat hotter there could be other factors as were the rifles properly maintained it’s service life, did it have range sessions like I mentioned that weakened components lots of variables

 

[Talyn]

The M855A1 has been around for awhile.

But, the new M7 & M250 using the new 6.8x51 came about because of the lack of lethal range issues encountered with the M4 in Afghanistan & Iraq.