I just modify the mag to fit the trunion as is. then it is also possable to do a screw build or have room for the rivet. also on aYugo trunion it would be possable to move the lower rear holes by the mag well forward and then the rivet or screw will not hit the mag. The main reason for using G3 mags IMOO is because they do not narrow at the front and will nwork for all fiamiter bullets from .44 down to .223. On oter mags the narrowing in the front prohibits using bigger OD bullets so if you wanted to do say a 358 WIN your out of luck because the fron hits the bullets. for a 243 or 308 a fal or m14 mag is a lot easier way to go as they fit better. in the big picture it dont really matter if themag is $2 or $20 when your building a $500-$1000 custom AK.