A SECRET WEAPON FOR CMMG MK57

With many of the special projectiles I'd useful — most notably the massive, 55 grain subsonic rounds from Detroit Ammo Co (not pictured) — the bullet-shaped grooves within the front of your FN magazine didn’t Participate in nicely.Both of those ProMags I applied worked flawlessly, and the factory 5-7 mag I'd didn't. I’ll confess my standard