Question on 5.56mm

[Jamie Young]

Does our military use 55gr FMJ or 62gr Steel Core bullets in the modern M16? I've heard stories about guys in Somolia shooting Bad Guys with the 62gr Steel Core and the Bullets were less effective? Is there any truth to this Story?

 

[dbrowne1]

The active duty troops that use the M16A2, M4 Carbine, and the M249 SAW are all issued M855 ammo which uses a 62 gr. SS109 bullet. Some NG units still have M16A1 which must use the 55 gr. M193 due to their slower barrel twist. M855 has a small steel penetrator in the tip, but is NOT armor piercing and you can buy it legally.
The stories from Somalia are due to two factors. First, a lot of the troops were using short barreled carbines that did not propel the M855 to its fragmentory velocity (of 2500-2700 FPS). Second, the Somalis were very thin and some were doped up.
Both 55 gr. M193 and M855, when propelled fast enough, will yaw and fragment violently in tissue causing severe wounds. Their wound profiles are nearly identical since the steel piece does not effect the mechanism that causes the bullet to break up. See:
http://www.fen.baynet.de/norbert.arnoldi/army/wound.html

Out of a 20" barrel, both rounds are effective to about 150-200 yards, and 100-150 out of a 16" barrel.

I'm always amazed at the folklore out there about the .223