Help needed please - Colt Model 1860 problem

[Brian the Brit]

I was just getting my Uberti revolver ready for a session at the range tomorrow when I noticed a problem that has me baffled.

When I pull the hammer to half cock the bolt locks the cylinder and the hammer will fall if the trigger is pulled.

I've pulled it apart and reassembled it a couple of times but the problem persists. I can't see anything wrong.

Am I being stupid and reassembling it wrongly or does this suggest that the bolt and or trigger and or hammer are worn and in need of replacement?

Looks my morning's shooting tomorrow is off unless I can get this solved in the meantime.

Any suggestions? I'd appreciate some help.

Brian

 

[Pearson]

If you didn't notice anything when you disassembled it, more than likely, the tip of the trigger (sear) is broken off. This makes the sear portion of the trigger too large to fit in the half cock notch. Either that or your half cock notch is peened over.
Mike Pearson

 

[mazo kid]

Yeah, definitely something wrong with the fit-up of the sear/hammer notches. How far down did you disassemble the gun for inspection? You will probably have to take the grip frame off for starters, so you can visually check what is happening.

 

[idahjo]

I was just getting my Uberti revolver ready for a session at the range tomorrow when I noticed a problem that has me baffled.

When I pull the hammer to half cock the bolt locks the cylinder and the hammer will fall if the trigger is pulled.

I've pulled it apart and reassembled it a couple of times but the problem persists. I can't see anything wrong.

Am I being stupid and reassembling it wrongly or does this suggest that the bolt and or trigger and or hammer are worn and in need of replacement?

Looks my morning's shooting tomorrow is off unless I can get this solved in the meantime.

Any suggestions? I'd appreciate some help.

Brian

Sounds to me like the half-cock lip broke off...
(pull the hammer out and look at it)

 

[Brian the Brit]

Well, I did get to the range on Saturday and had a good morning's shooting without any further problems.

It looks as though I was assembling the revolver incorrectly but I'm still not sure exactly what I was doing wrong.

I did notice though when I used a torch to look into the action that the edge of the bolt that engages on the cam on the hammer was looking worn and occasionally would slip over the cam rather than pivoting around it so I've ordered a new bolt and a set of new frame screws.

Fingers crossed.

 

[mykeal]

For American forum readers: torch in the UK means flashlight...

The problem with the bolt might be that the spring side needs to be 'adjusted'.

The bolt has two legs, as you know. One leg rides above the cam on the hammer; the other leg pushes against the frame wall. The purpose of this other leg is to keep the leg that rides above the cam in place, that is, flat against the hammer face. When viewed from the top the two legs should be slightly apart from parallel so that the other leg is held against the hammer. It might help to 'spread' those two legs a bit.

 

[Brian the Brit]

I'm pretty sure that the problem was as you describe, Mykeal. When I checked the bolt I found that the two arms were parallel but I was a bit nervous about bending them apart as I had a vision of the arm snapping off in my hand. The new bolt which arrived yesterday showed a pronounced splay between the two arms.

Anyway, I thought that as I had the new bolt I might as well put it in. Easier said than done though. The bolt needed quite a bit of filing and shaping before it worked properly. It took me ages and so many strip-downs and reassemblies before I got it right that I nearly gave up in frustration.

I found that the cylinder was not registering with the barrel but only by a tiny amount. The slightest hand pressure against the direction of rotation resulted in a nice click as the bolt latched.

Next I found that if I pulled back the hammer rapidly, the cylinder rotated well past battery.

It took only an incredibly small amount of filing to get from this stage to perfect timing though so all the effort was worthwhile.

At least now I appreciate the skill of the C19 gunsmiths who assembled old firearms by hand before parts were standardised and interchangeable and have a much better idea of how the deceptively simple mechanism works.

Thanks for the advice.

Brian

 

[mykeal]

And you now have a firearm that you have tuned with your own two hands and that you know intimately. You know how each part works and why. It's a remarkable, brilliantly simple yet effective design. Old Sam was quite a guy.

 

[crockett]

Yep- the later "Peacemaker" colts used about the same mechanics so if you get a book on tuning them it will apply to the percussion guns.

When you start to pull on the hammer the bolt should drop before much rotation takes place. You can see this on the cartridge guns but with percussion you need to slide some paper. etc in between the frame/cylinder area to verify. When the tail of the bolt slides off the cam the bolt should be in the lead cut, on a lot of guns the bolt pops up too early and scores the cylinder.
Next the bolt locks up and after that you shouldn't have to move the hammer much farther back (1/4" tops) before the hammer locks. The length of the hand also plays a role in all this. The width of the hand is also important because the end of the hand starts pushing the cylinder and then slides off and then the side of the hand keeps pushing.