i made a couple of 25 round mags that hooks up real tight in my g43 they seem to feed well by hand .With me working the bolt by hand,so who knows.Stunk up the kitchen last night baking the paint on ,that i got from brownells gun supply. Lots of metal grinding and a little silver soldering.seems to lock up very well ANYONE ELSE HAD ANY LUCK CONVERTING A MG13 MAG TO A G43