Replies

"I understand fire and maneuver, and the advantages of being able to carry and shoot more ammo, but one of the consistent post-Vietnam complaints about the M-16 was the lack of knock-down power of the 5.56 round compared to the 7.62 round of the AK-47. I'm sure the soviets had plenty of direct battlefield intel about the performance of the M-16; so I'm just surprised that they switched to a similarly-sized round after seeing the results of the American weapon for nearly 10 years. Either their analysis of the effectiveness of the 5.56 round was very different from the loud American criticisms, or they just ignored 10 years of direct observation. It's a puzzlement to me."

The 5.56 is plenty capable of rapid incapacitation, the issues revolve around bullet design. The original M-16 barely stabilized the bullet, so it often tumbled resulting in large wound channels and plenty of energy transfer. Not all that accurate, but if you hit the target results tended to be pretty good.

Once the bullet was better stabilized, it tended to pencil through. That's the source of the complaints you're citing.

I think the Soviets have a good bullet design for the AK-74 that will fly properly, but tend to tumble and fragment after impact.

There is at least one good military option for the M-4, the SOST round recently adopted by the Marines. The Army, on the other hand, may be in trouble with their most recent design, the M855A1, which also happens to be lead-free.

The M855A1 looks to be a turkey, costing twice as much as the SOST round, and running at 63,000 PSI which halves barrel life. It's also pretty poor at armor penetration.

Civilians have a lot of fine options for 5.56 bullets, as well as even better AR chamberings like the 6.5 Grendel.