ok, my socom 16 came with 1 20 rnd mag, so i bought 2 others: 1 springfield mag i could find and a promag 20 rnd the original springer mag clicks and locks if u put a little force onto it, however the other springfield and promag will click in the front but not click into the back and lock into place, the mag release never clicks back to lock the mag in, and i feel that the one that does seat does so with more force than such a nice rifle should need. also im new to the m1a are mags meant to be put in with the bolt lock back only? my question is to i start filing on the mag tabs a lil or is it to due with the mag release and i need to contact springfield? or maybe just get a aftermarket mag release and hope it works? also i want to change the socom gas block to the SEI Socom 16 Gas Lock, what is involved in changing that out? rifle is mostly fine. the mags, one that works is the left one. the gas lock that i want to change.