Ammo My Gun Likes!!

Well... I had bought some steel cased ammo and shot it through my M91-30 and as I had said in an earlier post that after I shot it it the bolt would be really hard to pull back and stuff.... So.. I got some replies that said shoot some brass cased ammo and see if it likes it. So.. today I picked up some and cleaned it again and when I shot it, it worked much better than before! So, now that I have found the ammo that my gun likes I can now buy alot of it off the net.
Thanks for the input.