K-Frame Fails To Fire.... Sometimes

[Enigma]

I have a 6" Model 10 - an old cop gun - that occasionally (say 10-15% of the time) will not fire in the single action mode. When you attempt to pull the trigger, there is a very small amount of perceptible movement, but the hammer will not disengage from the trigger. If you apply just the slightest bit of rearward pressure to the hammer and pull the trigger again, it will fire.

No problems when the hammer does fall - the gun fires every time.

It's got me stumped, so I thought I'd ask here. Anybody got any ideas what could be causing this?

 

[HEADKNOCKER]

I'd remove the sideplate & see if there's a stop rod inside the rebound slide.. If there is remove it..
Hard to say for sure..
Sounds like something is limiting the movement of parts internaly..
Could just be full of carbon/Rubbish

 

[tomcatt51]

I'd remove the sideplate & see if there's a stop rod inside the rebound slide.. If there is remove it..
Hard to say for sure..
Sounds like something is limiting the movement of parts internaly..
Could just be full of carbon/Rubbish

If there is a stop rod in the rebound slide the rod normally has a rounded end and a square end. The round end goes in first. If the rod was closely fitted that can be an issue.

 

[mmande]

As long as you have the rebound slide out, check to see if both ends of the rebound spring are ground flat. If they are not, it has been clipped to give a lighter trigger pull. Because it is too light then the trigger cannot get out of the way of the hammer falling, causing the hammer to catch on the trigger creating a misfire. Replace the rebound spring with a new one and the problem is solved. The trigger pull will be heavier, but it will fire every time.
Mike A.

 

[kscardsfan]

Get a copy of Patrick Sweeney's Gunsmithing pistols and revolvers book. He's got a few chapters on the Smith and Wesson wheel guns.

 

[Enigma]

I'll give those things a good eyeball when I return to the States; they wouldn't let me bring it (or anything else) to Korea with me.

I had the gunsmith install a set of aftermarket springs when he reblued the gun, so either a problem with the rebound spring or a limit rod are definite possibilities. Dirt or debris isn't a possibility, as he thoroughly cleaned everything before he blued it.

 

[kscardsfan]

Is it binding up or anything?