Originally Posted by
imarangemaster
I was talking to a guy at the Benning AMTU armory. He said that the main problem with the M855/SS109 is the short barrel. He said it works well (yawing and fragmenting) out of the 20 inch barrel. Out of the 14.5 M4 barrel, the velocity is insufficient past 75-80 yards to reliably yaw OR break up and fragment. The 5.56mm Open Tip, 77 grain MK262 Mod1 (from Black Hills) that they developed for the SAW works very well out to 150-200 yards even from the M4. It is an easy fix, but he says the brass is fighting it.