In its current configuration, it would need to have the action lengthened another 1/2" + to be able to load a straightwalled cartridge of the length and diameter of a 45 Colt.
I did a lot of measuring (hopefully better than my initial bore measurement) just to see what would fit the action as is. When making the turn from the top, any type of bottleneck facilitates the effort, therefore the 44-40 is good, but the 45 colt, with its greater base diameter and no bottleneck, is too snug to make the turn unless you deep seated to cut the OAL. The 44 spec and mag case, though straightwalled, are less in diameter and can be loaded shorter as well, so they would fit.
I had originally considered this as a donor for my experimental "25 Grinner" the alternative to the 22 rimfire, but once it was in hand, I started to reconsider, just because the bore looked too good to reline. Of course, as easy as it is to switch barrels, the Grinner may still come to fruition....
Any of the 32 cal rimmed pistol rounds, up to the 32 H&R mag, and 32 fed would fit OK, pressure permitting.
Again, another 1/2" in length would help all the way around for anyone thinking of going gonzo from scratch on a colt or for a more friendly 44-40.
It's perfect for the Grinner.
