If you decide to looking for 10 round mags leave the plastic ones alone. I did have good look with metal ones
The ones for a pump will work in a auto. They just won't hold the bolt open on the last shot
My experience also with plastic mags. I'll add that all you really need is a long action mag for any of the 7400 or 7600 lineage of rifles (6, 760, 7600, 740, 742, 750, etc etc).