bolt spring slipping off the hammer cam??

[Pulp]

On my Navy Knockoff the bolt spring is slipping off of the hammer cam at half cock. Is there any cure, other than a new hammer? I can ease off of the trigger/bolt spring and solve that problem, but then the bolt doesn't have enough tension to hold the cylinder at full cock.

 

[rcmodel]

It would seem the loading notch on the hammer is cut in the wrong place, or the end of the trigger (sear) is broke off.

Else the bolt arm could not be in a position where it could slip past the cam.

rc

 

[ClemBert]

You mean the bolt leg (not the trigger/bolt spring) is slipping off the hammer cam, right?

Is this new are did it always do this? Do you think the cam is worn out or do you think you can bend the bolt leg a little to resolve the problem?

 

[Pulp]

"You mean the bolt leg (not the trigger/bolt spring) is slipping off the hammer cam, right?

Is this new are did it always do this? Do you think the cam is worn out or do you think you can bend the bolt leg a little to resolve the problem? "

Sorry about the poor use of nomenclature.

I've had the gun about 8 years, used it extensively. I took it apart for cleaning the other day and the problem surfaced. There is some wear on the cam. By bending the bolt leg, do you mean spreading it a bit?

 

[ClemBert]

There's two things I had in mind.

1. Spreading the legs. Specifically so the bolt leg applies more pressure to the hammer side surface.

2. Bending the tip of the bolt leg so that it fully locks over the cam. It sounds like the bolt leg that is supposed to slide over the cam isn't quite making it. All it takes is 0.001" and that could make the difference between working and not working.

I had various similar type issues as can be read about in this thread. Read through it....you'll see at first it started as a bolt locking issue that morphed into a problem similar to yours.

Just to be clear...we aren't talking about whether or not the hammer stays at the half cocked position we are taking about a bolt-leg/hammer-cam issue...correct?

 

[TheRodDoc]

This is the way the bolts get bent on the copys. They arn't quite hard enough. And must be bent back the direction of arrow to drop the bolt later. Not sideways. This is exzagerated in drawing for in real life it won't show up by eye much. only takes a very slight bend to make a difference.

If it is a colt it will most likely brake if you try to bend it for they are harder.

View attachment 124762

 

[Pulp]

10X magnification on the hammer cam shows me I probably just need to order a new hammer. I tried spreading the bolt legs to get a bit more tension, but it didn't help.

I've put a lot of rounds through this gun through the years, so I'm not surprised parts are wearing down.

One thing just came to mind. Would "frame stretching" cause this problem? I've never babied this gun with light loads. Cylinder gap is still very tight, so I don't think it's stretched, but I'm not a gunsmith either.

 

[ClemBert]

But maybe the bolt leg isn't going far enough over the cam to "catch" properly. If that is the case then bend the bolt leg a tiny amount. On a firm flat surface with something under the bolt head and the bolt legs (to prevent marring) gently whack with a light hammer in the direction indicated to bend the bolt legs.



Or maybe...as you indicated you need a new hammer. It is possible to add material to the cam if it is worn. It would be basically a solder/brazing job. Then file down to size.

 

[denster]

Most likely the hammer cam is not the problem and you need a new bolt. The cam on the hammer is very hard while the bolt has been hardened and drawen back to a spring temper making it the softer part that wears first. Bending the legs is at best a very temporary fix when it works at all.
If this is a Pietta you can get a spare parts kit from Cabela's that has hammer, hand, bolt, trigger, mainspring and bolt trigger spring for $29 which is only a few bucks more than it would cost to order the bolt alone from VTI and pay thier shipping.

 

[Pulp]

I think the kit from Pietta is the way I'll end up going. I tried Clembert's tricks, neither worked.

I appreciate all the input, as always, I get good information here.

 

[ClemBert]

Yeah, that Pietta replacement parts kits is fairly inexpensive. Don't be surprised though if you find you have to make some slight adjustments to the new parts. From what I can tell this isn't uncommon. Keep us posted as to how it turns out.

 

[madcratebuilder]

You can replace just the hammer cam.

http://www.dixiegunworks.com/product_info.php?cPath=22_434_435_440&products_id=1069

You may have a wear issue on the bolt leg. Hammer cams are pretty hard. I have had a few Colt clones that would drop the bolt early, I would add preload to the bolt leg. That has worked for me anyway.

 

[denster]

Madcratebuilder brings up some good points. There is considerable clearance between the frame and the hammer generally about .183 and the bolt is only about .155. Pre-loading the leg or bending it outward untill the measurement ovcer the legs is about .175 works but to do it right you have toi anneal the bolt, bend the leg, reharden the bolt then draw it back at about 725f to a spring temper for it to work in the long term. Uberti bolts generally come this way Piettas don't.
You can replace the cam but with most of the repos the cam is milled out of the hammer not pressed in. You have to center drill the old cam through the hammer to about .0005 smaller than the new cam, grind off the remaining cam, lightly camfer the cam hole, heat the hammer and chill the new cam then press it into place, Sounds harder than it is if you have the right tools.