[Farmer Dean]

I’ve always preferred the M193 load in our ARs and M16.The bullet usually breaks up on impact,at least at close range.For serious zombie kills,I’ll use my Remington 700 tactical in .308 or my HK91 if they start getting too close.

[FlyVet]

I bought a load of the Hornady 55 grain FMJ a few years ago, and yes, fired through test media, they penetrate a few inches, and then yaw and fragment violently. I should not like to be smitten with one of them at close range, either.

It seems our troops have the most problems with the M855 out of an M4 14" barrel. They tend to drill through and make pencil holes sometimes. The FMJ need higher velocity to upset and do damage, more like the A1 with its 20" barrel length. The closer to 3000+ fps at impact, the better. Can't get rifle performance from a long pistol barrel.

Since the troopers like compact rifles so much, I wish they'd come up with an ambidextrous bullpup design for them, much like the Kel-Tec MFB. Then, they could have a 24" barrel, lightweight and compact, and all the velocity they need.