Hi all. I recently, purchased a S&W Model 10-5 revolver from a guy. The previous only reported that the gun has a trigger reset issue possibly due to dirty mechanism. Being mechanically curious, I followed the youtube video on disassembly the Model 10. I found the gun internal is clean and the reset problem attributed to the hammer block.

The trigger reset issue arise if one pulls the trigger from either SA or DA mode and slowly release the trigger. If I release trigger slowly, the hammer block would bind against the hammer causing the trigger failed to reset completely (stopped approximately 1/3 of the way) This can be fixed by manually reset the trigger or pull the hammer back even with a simple light touch to the spur.


SW 10 5 Trigger Reset issue - YouTube


I did notice the corner the hammer safety block interact with the hammer is flat and sharp, is that normal? I'm suspecting that is the chief reason why the reset issue is arising from. I purchased a replacement hammer safety block. However, it was the wrong model (meant for the ones with frame mounted firing pin).
Would it be correct to file the hammer safety block slightly in a 45 degree angle to correct this issue?

There are two possible problems. First, the rebound slide is called that because it is the mechanism that causes the hammer to rebound! To do it the rebound slide spring must have enough power to overcome the pressure of the mainspring. In simple terms, the rebound slide "interferes" with tha hammer because it is supposed to. Solution, buy a new standard weight rebound slide spring and the "problem" will go away.

This often happens when "Bubba", not knowing what he is doing, does a "trigger job" by changing springs without understanding the operation of the mechanism. The trigger won't recover properly and Bubba is too stupid to realize that what he did is what caused the problem and he sells the gun! Hope the price was real good!

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Gunsmithing since 1961

Are the internals properly lubricated? If not, lube them then do a lot of dry fire.

Agree with Post 2. This revolver likely does NOT have any problem with the hammer block. Instead, this revolver needs a full power rebound spring. If that part was replaced, it is likely that the main spring was replaced also if a previous owner installed a "spring kit." Were it mine, I would see that the rebound spring and the main spring were replaced with factory originals.

There are no S&W recommendations regarding the lubrication of internals. If it's under the side plate, it doesn't get greased . . .

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Wisdom comes thru fear . . .

Moving parts need to be lubricated.

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PM me and I'll send you a good rebound spring.

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-jwk-
US Army '72-'95

Check that the trigger and hammer pivot pins welded to the frame are not bent or deformed.

Thanks for all the fast response. When I took the side plate out the parts are all lubricated. I did not remove each individual part as I didn't believe it was necessary but I applied lube at all the point where it interact with another. I did notice lubing does decrease the symptom but does not completely remove the problem.
Based on the appearance of the part, everything appeared to be original (with exception of the barrel itself because of Canadian minimum handgun barrel length requirement). Is it possible that the rebound spring wears out overtime? Based on the fact its a 10-5, I'm fairly confident to say it is older than I am.

I would order a new spring from S&W, or order a spring kit from Wolff and use the highest power return spring in the kit.

My guess would be that, rather than a replacement spring failing to reset the trigger, someone got carried away grinding coils off the stock spring. Just a guess, though.

My experience has been that the very lowest power spring in the replacement kits will always reset the trigger, especially when it is cycled very slowly. The problem comes with rapid fire . . . . it is possible to "outrun" the low powered springs, meaning they don't reset the trigger as fast as the shooter can cycle the action.

Anyhow, if the studs aren't warped out of shape, and crud isn't slowing the action, I bet a new spring cures the problem.

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Georgia On My Mind

Not in this case. The movement of the rebound is improved by stoning the surface. At most, a drop on the studs is all that is even begrudgingly recommended. There is no oil of any type on the student benches at the S&W revolver armorer's classroom in Springfield.

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Wisdom comes thru fear . . .

In the old days, before "spring kits", we used to pull the rebound block out and take the rebound spring and clip a coil or two off to lighten the double action pull. Sometimes, we went too far, and the trigger needed a little help to return to it's normal position. Our remedy in those days was a new rebound spring (we kept a supply). A new rebound spring will probably do wonders for you revolver.

Muss Muggins, lawdy, lawdy, I've always shot some spray lube in there and buttoned it back up. What harm can it do? It dries and leaves a rust preventative coat. All these years of erring! It makes me feel better to put something on there!

I've had two Model 10's with trigger reset issues when I got them. Although not new, neither had been shot enough to wear them in. After some shooting the problem went away in each.

Now that's interesting.
I have heard of 1911s needing to be broken in, but
I've never, ever heard about S&W revolvers needing to
be "worn in" before the trigger would reset.

I bought a Model 10-7 once that appeared to be unfired. After
the first few rounds I fired, the action began to feel like it wanted
to bind. I took the side-plate off and the action was bone-dry, with
some flecks of rust that were apparently causing the binding. A good
cleaning and a little lube () fixed things right up. I had the same issue,
cured by the same remedy, with a Model 28-2 I believed to be unfired.

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Georgia On My Mind

Among other things, check to be sure the mainspring tension screw is screwed all the way in and/or the screw has not been shortened. Morons loosen it to lessen the pull, and it can create a variety of ills.

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Pisgah

Welcome to the Forum, movieguns.

The hammer and trigger studs are pressed into the frame, not welded. Some of the older, pre WW II studs were screwed into the frame.

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John 3:16
WAR EAGLE!