We have been covering the US Army’s latest M855A1 and M80A1 “Enhanced Performance Rounds” (EPRs) here at TFB for the past few years. We’ve seen how in independent tests both M855A1 and M80A1 fragment early, thanks to their yaw-independent characteristics and special jacket design. One question that has not been answered publicly, however, is at what point do these rounds fail to fragment and upset; in other words, at what velocities do the EPRs not have enough gas to create the kinds of dramatic terminal effects we’ve so far seen from them?
William of The Wound Channel set out to test this by loading the 130gr M80A1 projectile into .300 Blackout cases, and firing them at ClearBallistics gelatin. The results he got, shown in the video embedded below, were quite impressive:
Even at 1,929 ft/s muzzle velocity, more than 1,100 ft/s slower than the muzzle velocity of 7.62×51 M80A1 Ball, the M80A1 projectile still fragmented, yawed, and both its penetrator and slug made a complete penetration of the gel block. That’s good news for .300 Blackout shooter who want an effective, fragmenting projectile with decent AP capabilities, but what does it mean for the fragmentation range of the M80A1 and even M855A1 EPRs? Well, the ballistic coefficient of M80A1 isn’t yet known, but even with a conservative 0.185 G7 BC, complete fragmentation at 1,929 ft/s like we see here would represent at least 430 meters of solid fragmentation range for the new 7.62x51mm round, which is not just good, but unprecedented.
We can’t be sure that the same is true for M855A1, but both rounds do share the same basic design. If we assume that M855A1 also fragments at such low velocities, this is great news for troops equipped with that ammunition, as that would extend the fragmentation range of the M4 all the way out to 340 meters or beyond. This is a huge improvement, as the M80A1 shown here exhibits similar fragmentation at just over 1,900 ft/s as the older M193 or M855 rounds do at muzzle velocities of about 2,600 ft/s!