1860 problem

[charliek]

I have a Pietta 1860 Army which I got cheap because it didn't work. I thought I knew what was wrong and could fix it. You know that story. The problem is that when the hammer is forward the bolt is up. Pulling the hammer to half-cock drops the bolt. But when the hammer is pulled to full cock the bolt fails to rise so that the cylinder is free to turn instead of being locked in place. I have replaced the bolt, the bolt spring and the hammer but that has not changed the problem. I have been through Kuhnhausen's book on Colts and know what is supposed to happen with the cam on the hammer and the end of the bolt spring, but I don't know why it doesn't work that way. Any suggestions would be appreciated.
Charlie

 

[No Grease]

Of this I am curious also for I have a brass frame Army with the same problem. :hatsoff:

 

[John Taylor]

The bolts need to filed to fit and be in time. Most replacement bolts are a little oversize to allow for fitting.

 

[mykeal]

John Taylor is correct.

One side of the bolt arm rides on the cam on the side of the hammer. As the hammer is pulled back the arm is forced up by the cam, causing the bolt to be retracted inside the frame. The cam is beveled such that when the hammer reaches full cock the bolt arm slips off the cam and the bolt snaps back into place from the force applied by the bolt spring.

There could be two things wrong: either the spring is broken (or if it's too straight to put a load on the bolt) or the bolt arm is not slipping off the hammer cam at the full cock point.

Be sure the bolt arms are not parallel (they should be slightly apart from parallel) and the bolt spring is bent and causing the bolt to be forced out of the hole in the frame. You should be able to see (with a flashlight) if the bolt arm is riding properly on the hammer cam (the cam should fit inside the curve on the end of the bolt arm when fully forward) and if it slips off the cam when the hammer reaches full cock. It may be necessary to remove some material on the bolt arm to get it to fit on the hammer cam properly and/or to fall off at the proper point.

 

[John Taylor]

Thanks mykeal, I should have given more detail on this but was pressed for time. It would be great if instructions were given with new bolts for fitting, but as with most gun parts it is assumed the buyer knows how to fit them.
It might help if you look at a revolver that is working right to get an idea of when the bolt is let go by the hammer cam, should be just before the trigger gets to the full cock position. To early and you get a ring on the cylinder and to late the cylinder will go past and not lock up. Proper timing on a revolver includes the bolt, hand and trigger. If the gun is timed right the hammer will not go back further after the trigger has dropped into the full cock notch. The bolt has already "dropped" into the notch in the cylinder and the hand can not turn it anymore. The hand being connected to the hammer will not let it move any more. Lots of area for problems when timing a revolver.

 

[charliek]

Thanks to you both. Comparing the problem gun with one that works I can see that what you are describing is the issue. Much obliged.
Charlie