I bought one the other day, a lancer, I have to smack the shit out of it to fit into my colt. which ive never had issues with mag fitment on. Also tried it on another lower and it was better but still needed to be smacked. Weird cus I've heard all the positive comments about them, maybe I got a lemon?Most of my stored AR mags are Lancers.
They worked in every AR I have. And in Cetme L, which is very picky about mags.