While I have run an M16 I never have been a fan of 5.56. I know that now, in 2019 there are a number of better AR platform ammo choices but back in the day, those didn’t exist. My option to that was this purchase I made back in 1980 at Martin B Retting for the princely sum of $410. What other options to the M4 platform for defense are you using or considering for purchase?