I tuned a couple of those Butterfields about 7 or 8 years ago. Nice revolvers. Well, it's more my "experience" with them. They tend to be all over the map with spring tensions. I've got a pair here with about 8-9 lb hammer draws . . . a pair of Dragoons that are about 5lbs hammer draw. The screw holes in the bolt many times are so close to breaking through, sometimes they are cracked there, . . . The parts overall are very rough especially compared to today's Uberti parts.Some of the F series are also lettered Colts. I don’t know why but I keep stumbling across the darn things. Have three of the 5.5” Butterfield Stage commemoratives and several (5 I think) of the full length 8” 1860 Army revolvers. Goon doesn’t have a very high opinion of the 2nd Gen guns but I’ve been pretty lucky with those I’ve picked up. I have sold a few that I wasn’t necessarily impressed with but for the money I like em… and they’re well ahead of any Pietta 1860 I’ve ever seen in form and function combined.
Something to look for - the arbor hole is almost always broken through to the loading lever cutout in the barrel assembly. Just things you wouldn't find in even other reproductions back then. But, like I said, it's not up to me, if you like um that's fine, I still work on them . . . most folks won't work on any of the early revolvers any more.
I just finished one today that's on its way back home. It came here with a bent arbor, locking notches that had to be recut basically (because of the ill timed bolt moving metal into the notch). The bolt itself wasn't a factory part. The front triggguard screw was broken so I replaced it for him . . . It was such a wreck!!!
Needless to say, it now has perfect timing, a straight and correct length arbor, a 4lb hammer draw and a 2 1/2lb trigger pull.
That's worse than most of course but not far off !!! Lol
Mike