As a helpful tip, those older Marlins will NOT feed most of the current Winchester bulk ammo, the nose is too blunt, and the feed ramp will NOT accomodate the flatter nose, same with the Winchester Power Point ammo. Don't even bother trying the stuff, period.
Federal bulk ammo does not suffer the same malady, and will probably feed okay. CCI MiniMags definitely will feed okay, and the Marlins like a snappy load like them. I'd skip Stingers and other hypervelocity stuff, too, they weren't made for it.
I've shot standard velocity ammo in mine a time or two, along with trying subsonic ammo, but they just aren't "zippy" enough to keep it working right.
Use the roundest-nose ammo you can find, high velocity, preferably, and it should run pretty well. Deviate from that, and expect it to choke and puke somewhat.
