I shot a NCOWS event yesterday with a Rossi 92 in 45 Colt. I had the same problem and didn't have last season at all. So I got to looking and found it was the length of the ammo for sure. In my case a 1.500" to 1.600" works perfect however if .001 less or more it doesn't and double feeds. Never had a problem with it with factory ammo but recently bought a press that came with a few hundred rounds already made up. They fired fine in my hand gun just wouldn't in the rifle unless they fell in the range listed earlier.
Just set your bullet seating die to the right length, then run all those rounds through it. That way you can be sure everything will feed.
It's funny, I started with a 92 in 45LC & never worried about ammo OAL. That rifle feeds anything, including semi-wadcutters. I bought an 1860 Henry back in February. First time I shot it, JAM. Ammo too long. I reset the bullet seater for an OAL of 1.570" & ran every round of ammo back through the press. I haven't had a problem with ammo jams since.