LITTLE KNOWN FACTS ABOUT CMMG MK57.

With some of the exceptional projectiles I had helpful — most notably the large, 55 grain subsonic rounds from Detroit Ammo Co (not pictured) — the bullet-formed grooves within the front with the FN magazine didn’t Enjoy properly.The projectiles would stick or drag in there and also the follower would bind. As being the ProMags have no inward