Thanks again guys
I'm THINKING it might be a .31. I had some .32 S&W long ammo laying around that matches up better to the bore than something in the .35+ range. It certainly doesn't look like a .357 bullet would fit in there, so I'm guessing it's .31.
Doc, no worries about not liking the engraving. Honestly, i think they are hokey as well. While I much prefer the look of unfluted cylinders, I really dislike all the "decoration" on these models. I will say the little scroll work and hashes on the brass from and barrel do add a little something to the gun, but a bunch of pioneers being gunned down?
...or was this marketing on the gun. "If only these poor souls would have been at least armed with a pocket Colt!"
I do want to thank you all again. It looks like I'll be shooting this one once I get some ammo in. While I would have never bought one this small, I have to say that I haven't put this thing down since I unzipped the case yesterday. It walks and talks like a champ even with all the wear on it. The frame and steel cleaned up pretty nice, too. The nipples appear to be flattened. This could be from a lot of use, or too much full on dry firing. At any rate, my #11s fit just fine, but I do get a bit of typical "colt binding" unless i give the gun a good robust shake vertically between shots.
I might have to get an 1860 next to compliment this lil bugger. Heck, my birthday is coming up in a couple months. Maybe I can sweet talk the wife into letting me plunk down the scratch for a Walker