M855A1 Review

This is a guest post by Andrew BettsM855A1 Review

M855A1 Review

In recent years, the US Army has adopted a new type of ammunition for its 5.56x45mm rifles and machine guns, which has attracted significant criticism, both because of the procurement process, and because of questions about the round’s actual performance. Why did the Army choose M855A1 and does it perform any better than M855? Are your tax dollars being spent wisely or is this simply feel-good tree hugger appeasement?

The new ammunition is a lead free design that is composed of a copper jacket, copper core, and steel penetrator that protrudes from the front portion of the bullet. It is intended to offer improved terminal performance as well as improved barrier performance while maintaining similar external ballistic characteristics and reducing toxic metal contamination on training ranges. There is little publicly available test data about its performance, though. This is the only known gelatin test of the ammunition available on YouTube:

It is difficult to draw conclusions from a test of one round, but that certainly looks impressive. The velocity is consistent with original M855 and the fragmentation and temporary stretch cavity is quite impressive.  The total penetration is also excellent for a military round. How does that compare to the original M855, though?

M855A1 Review

M855A1 Gel Shot

So the original M855 seems that it would do an adequate job but really is nowhere near as impressive as M855A1. Even at extreme close range, M855 only began to upset after about 4.5” of penetration. That could easily represent a small, through and through “ice pick” wound in a limb and even in the torso it could do minimal damage before exit. The M855A1 began to upset and fragment almost immediately upon entering the gelatin and the area disrupted was significantly larger, meaning that it would be more likely to produce incapacitating wounds. At least as it regards terminal performance, this seems to have been a solid choice for the Army.

M855A1 is said to have a similar trajectory to M855, as it should with the same projectile weight and similar velocity but reports from the field indicate the trajectory differs somewhat, with the

M855A1 Review

M855A1 Penetrator

M855A1 striking the target higher than M855. Still, soldiers qualifying with it indicate significantly better accuracy than M855. Earlier lots were extremely high pressure but recent production is reported to have much lower pressure. Nevertheless, it is higher than the pressures produced by M193 and M855 (or Mk262 and Mk318 for that matter) and it is said to significantly increase barrel wear. It is the same weight as M855 but has no lead so it is necessarily longer. That means a longer bearing surface with more friction and a higher pressure is necessary to achieve the same velocity.

So how did the Army arrive at this point? When the M16 was first fielded, it was issued with M193 55 gr FMJ ammunition. This ammunition fragmented reliably at ranges of 150 meters or less when fired from a 20” barrel so it was very effective on exposed targets. It was considered to be lacking somewhat in penetration of hard obstacles, though, so when the Army went looking for a light machine gun to replace the 7.62x51mm M60 at the squad level, Fabrique Nationale decided to address that shortcoming by producing a new type of ammunition, dubbed SS109. It had a traditional lead core and copper jacket along with a small steel cone in the tip of the projectile inside the jacket. This ammunition type, given the nomenclature M855 in the US, was adopted by most NATO member nations and was the primary type of 5.56mm ammunition issued to US troops for several decades.

M855A1 Review

M855A1 Copper Core

M855 had some of its own flaws, though. One significant problem was that its ability to fragment, and thus its ability to incapacitate quickly, was somewhat erratic. When it did fragment, it typically did so only after penetrating fairly deeply into the target, as we saw in the test above. This erratic behavior was reported by troops in Somalia, Iraq, and Afghanistan. Sometimes the ammunition would work well and put a target down with one or two good torso hits but other times even multiple hits to the chest would leave the enemy fighting for several minutes with small, .22lr-like wounds. The Army was also facing some political pressures to move to a lead free bullet for environmental reasons.

At the same time, Liberty Defense developed a novel type of ammunition that was composed of a copper jacket, tin/bismuth core, and steel penetrator tip that protruded from the jacket at the front. If this sounds familiar, it should, because the construction was identical to the original M855A1. It was only after some testing of the tin/bismuth core M855A1 that the DoD decided they would see better performance with the copper core.

This brazen theft of intellectual property cost the DoD (and therefore US taxpayers) $15 million in addition to a 1.4¢ per round royalty for all future M855A1 ammunition purchased by the DoD after a federal court ruled in Liberty’s favor. Because Liberty owns the intellectual property, there appears to be nothing to prevent them selling this ammunition to the public (subject to ITAR, of course), but they have made no indication that they intend to do so.

For the moment, this ammunition is out of reach for the proletariat. Still, we have had much better choices available for quite some time. If penetration is a priority, M995 true armor piercing is available for sale, though expensive. If terminal effect and barrier performance are a priority, 64 gr TBBC or Fusion/Gold Dot are much better performers. There are too many to list but civilians have the luxury of choosing from a vast array of loads that can be tailored to precisely their needs.

Is it worth the expenditure of public funds, though? On the one hand, it is very encouraging to see our war fighters finally issued accurate ammunition with good terminal effect. While M855 is not terrible, it is far from ideal and it has been frustrating to know that there is no technical reason that our soldiers and marines should be saddled with substandard ammunition.

From an engineering standpoint, it seems a panacea. It penetrates hard obstacles better than M855, is more accurate, has better terminal effect, and to top it all off there is no lead in it so it doesn’t make unicorns cry. Because of that lead free construction, though, it costs much more than M855 and the royalty imposed by the court increases the cost even further. Worse, it wears out barrels, requiring replacement earlier in their service life. To say the very least, there are significant financial disadvantages to the adoption of M855A1. Whether those costs are worth the performance gain is something the taxpayers will have to decide.


Andrew Betts served with the Arizona National Guard for over 12 years, including a tour to Afghanistan. Visit his YouTube Channel for more great shooting information.

Photo credit – Andrew Betts

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