Over-cocking?

[socal s&w]

I have done some smoothing of many S&W revolvers so a buddy asked if I could give installing a new hand a whirl. Never tried it before and it doesn't involve any frame work, so I gave it a go.

After receiving the hand, I fit it to the action by matching a known hand and fine tuned it to that revolver and it seems to work fine in both single and double action.

Problem is that it can be 'over-cocked' meaning that the hammer can go past the single action stop when manually cocking the revolver for single action. I checked with another revolver of the same frame and it appears that the hammer is basically stopped by touching the frame where the rear of the hammer is 'V-ed'. It may have had this issue before I took it on, but I don't know since it was not discussed, nor did I check. (I prolly should have I now know.)

Is there something that I'm missing here? What is the fix?

 

[GLV]

Despurred ??

I have seen this problem when a hammer was despurred and in polishing, material was removed in the area under the spur.

 

[dfariswheel]

Some S&W revolvers hammer spur will contact the rear of the frame.
Most S&W's hammer will be stopped by the "Vee" area of the hammer contacting the back of the hammer slot in the frame, but, with some it's the spur that makes contact first.

I have two like new S&W Model 66 revolvers. One is a Dash-2, 2 1/2" and the other is a Dash-3, 3".
The 2 1/2" Dash-2 stops with the "Vee area on the hammer slot, the 3" Dash-3 stops with the underside of the hammer spur on the back of the frame.

 

[socal s&w]

Thank you for the replies so far.

The revolver that I'm working is a Model 10-7. It was an old range gun that needed a 'hand'.

The spur is still place and nothing has been done to the hammer. No smoothing of the action has occurred and there are no 'extra' marks on the hammer, nor anywhere within the action that I can tell.

It appears to align with the firing pin bushing hole when in the down position, but seems to be too large since the Veed part is too far from the frame when fulling cocking single action to stop it at the correct position.

Any other ideas?

 

[dfariswheel]

In almost all brands of revolvers, what stops rearward movement of the hammer is the hammer contacting the rear of the hammer slot in the frame.
I don't recall any revolver that has some sort of internal hammer stop system to stop rearward movement.

If any DA revolver would stop the hammer due to the fit of the hand, it would be the old Colt action as used on the Python, and the Python hammer stops when it contacts the rear of the hammer slot.

In other words, nothing is wrong with the gun, it's normal.

 

[tomcatt51]

Any other ideas?

Actually a question. What are you calling "over cocking"?

Does the hammer just pull back (farther than where it rests cocked on the hammer notch) and then move forward onto the notch and have a normal SA let-off?

Or does the hammer move back too far and stay there giving a funky SA let-off?

 

[socal s&w]

Actually a question. What are you calling "over cocking"?

Does the hammer just pull back (farther than where it rests cocked on the hammer notch) and then move forward onto the notch and have a normal SA let-off?

Or does the hammer move back too far and stay there giving a funky SA let-off?

It does the latter, it lets off a funky single action let off, the hammer actually goes rearward just a little farther when pulling the trigger in single action mode and then releases forward before going home to the bushing/firing position. It single action cocks past the single action stage by allowing the hammer to go completely beyond that point, the single action sear is nowhere near it's resting point, the hammer is completely free of the single action sear and is about at the point one might use to remove the hammer from the gun. The trigger sear actually sits on the bottom of the hammer, not the hammer sear. Do you think that the hammer is wrong for the model? It looks right and aligns with the bushing when in the firing position.

 

[tomcatt51]

It single action cocks past the single action stage by allowing the hammer to go completely beyond that point, the single action sear is nowhere near it's resting point,Do you think that the hammer is wrong for the model?

Well, I understand what you're seeing. Some of my bobbed hammers (depending on how they're cut) and all the radically lightened hammers will do what you describe if one (foolishly) decides to pull the hammer back for SA.

Does the gun "cock" correctly and have a good SA let-off if you don't pull the hammer back "too far"?

 

[socal s&w]

Does the gun "cock" correctly and have a good SA let-off if you don't pull the hammer back "too far"?

It does....it's just super easy to pull it back too far, there is very little margin for error there.

Hammer is a standard, non-bobbed, non-skeletonized hammer.

Thanks!

 

[tomcatt51]

Sounds like you may just have a tolerance stacking issue. The "good old hand fitted" guns really weren't, they were "selct fit". You start with boxes of parts made to questionable tolerances and try them until you get a combination of parts that work together. Sounds like you have a hammer/frame pairing that lets the hammer pull back too far. If you pull the sideplate (and the springs) you can see the trigger hook / hammer notch relationship as you pull the hammer back.

A carefully fitted (for length) trigger stop rod inside the rebound spring would "fix" your issue. Could one have fallen out when you dis-assembled the gun?

 

[socal s&w]

A carefully fitted (for length) trigger stop rod inside the rebound spring would "fix" your issue. Could one have fallen out when you dis-assembled the gun?

I suppose that it could have although I am familiar with the innards if the revolver and use a rebound removal tool. I am very cautious in knowing that many, not all have that stop within the spring.

It also doesn't mean that someone else may not have had this apart being a range gun....you never know who worked on something like that.

I could try the 'fix' though and thank you for you comments and input dealing with my issue/s.