Anybody know the actual chamber size of my RRA LAR15
I've built an SBR using a RRA LAR15 A4 upper and lower. I want to know what it's chambered for and have read conflicting information. 5.56 and .223 are not exactly the same. I understand that it's fine to run .223 ammo through a 5.56, but the opposite is not advisable. On RRA's website they list the chambering as .223/5.56, well which is it? Has any body measured it? The lower is marked 5.56. I've also built an LMT MRP in sort of an SPR fashion. I know it's chambered in 5.56. I want to knowif I can feed both of these 5.56 ammo. Any info would be appreciated.:confused: I've been reading here for a long time, but posting little. I'm going to put my pics up soon.