So this is a magazine well insert that allows a std AR lower to accept HK USC mags. Supposedly, these will work with a CMMG RDB bolt/barrel.
Anyone ever tried these?? I am thinking about rolling the dice on one for my CMMG bolt and barrel I have laying around.
Anyone ever tried these?? I am thinking about rolling the dice on one for my CMMG bolt and barrel I have laying around.