Free: Contests & Raffles.
The Model 12 is more likely than not S, L, LR. They made Model 12 gallery guns chambered in S only though. CCI SV 22 LR is what I would shoot in it. The Remington looks to me to be a Model 4, I’m not an expert on rollers, but believe the Model 6 (a tiny little gun) was also available. The Model 4 is a fairly robust rifle, but I’d favor shooting SV ammo in it as well. Hopefully the bore in them is in good shape. If it looks bad on any it may still shoot surprisingly well… or not. With CB loads, make sure the bullet makes it out of the barrel and isn’t stuck in the barrel on each shot before shooting another round.
I love old 22's, those are very cool