New m27 trigger question

[jtmo3]

I have a new m27 s&w that I've put about 750 rounds through. The trigger is a little heavy but it's fairly smooth and I can live with that. The single action is pretty good. The problem is with the da trigger. After the action is staged, the last 1/8" or so is really rough ad gritty feeling. I've had the sideplate off twice to clean and re-oil, but it hasn't helped. What is it that I would need to do to smooth up that last 1/8" or so of the trigger? Thanks.

John

 

[Jim K]

Normally, MIM parts are fairly smooth, not having tool marks like the old machined parts. Still, any part can be rough, and I think some careful stoning would smooth that trigger a lot. Other possible steps are the usual, reducing mainspring tension by grinding the sides of the spring and lessening the tension of the trigger return spring by careful grinding on its sides (not clipping off coils). An alternative is to buy a spring kit that has less stiff springs and install it. Either way might induce some slight risk of failures to fire if the gun is used under adverse conditions.

Jim

 

[rcmodel]

Stoning on S&W trigger parts is risky business.
On the pre-MIM parts you can easily cut through the case hardening and ruin them.

Don't know about the MIM stuff, but it is very hard to control the angles without a high-dollar sear / trigger jig.

Light gun oil hasen't got much film strength.
Lube it with Gun-Slick graphite grease and shooting it another couple thousand rounds is your best bet.

rc

 

[Oro]

On the pre-MIM parts you can easily cut through the case hardening and ruin them.

That is my biggest fear when it comes to S&W triggers/sears. Unless I have the ability to re-harden them at home (I do not), I don't touch them. They can become junk in just a few file strokes.

The six-shot 27 has, by it's nature, about the heaviest trigger trigger you can get on a standard S&W revolver (most mass to push). When you opened it up, did you examine the rebound slide for burrs? Stoning that piece smooth on the sides and breaking the edge on the corners can sometimes take away the "grittiness." Then do the same for the channels it rides in on the frame and sideplate, as well as the rebound spring within the slide - no burrs. Grease them all lightly and re-assemble, like rcmodel said. These parts have a high shear force and need a grease around them, not an oil. A flat stone and a glass table top or similar to check your work is very helpful here.

Tip - for getting the rebound slide back in, a 3/32" or 1/4" tapered punch works about as well as the specialized tool, and is safer than a screwdriver. But a screwdriver will do in a pinch when used by careful hands.

 

[krs]

Oro:"They can become junk in just a few file strokes".

Oro, my friend, please tell me that you would never use a file on any part under the side cover...

 

[jtmo3]

OK, follow up to original question. I took the gun to a buddy who know a bit about revolvers and had him do some clean up on the insides to smooth the trigger some. The trigger is smoother until the last 1/16 to 1/8" pull. He determined that the issue is with the timing. The cylinder is locking up slightly before the hand is all the way up moving the cylinder around. the roughness is the hand still pushing on the already locked up teeth on the cylinder. He said you can get different length and size hands but I don't see any listed other than a standard hand and an oversized. It appears that the hand would have to be shorter or you would have to grind on the teeth and that I'm not going to do.

Anybody have any idea here other than calling S&W to see about getting the hands? I could send it back to them but we've opened it up and worked on the insides so the warranty is dead at this point.

Thanks.

John

 

[Old Fuff]

Your friend is apparently unaware that the hand is supposed to keep moving upward after the cylinder has been locked. However the roughness you describe can be caused by the side of the hand rubbing on the side of a ratchet tooth. Try this experiment to see.

Swing out the cylinder, and while holding the latch thumbpiece fully to the rear, double-action the trigger and see if things feel different. If the pull is smoother you probably have found the reason for the roughness.

A less likely cause might be that the hand is rubbing on the side of the window in the frame it moves through.

Given the fact that the revolver is new, and expensive, and someone making the wrong correction can ruin it, I would return it to Smith & Wesson. They will pay for all expenses, including shipping. While waiting to get it back is a pain in the backside, it is far better that any correction is done right, rather then simply done...

I doubt that your warrantee is dead if the cause of the problem is a something related to the revolver's original assembly.

 

[jtmo3]

Thanks Old Fuff. I have done that experiment and the action is very smooth with no roughness with the cylinder out. The window was stoned and is not rubbing. I understand? that the cylinder should lock up just slightly before the hammer drops. This one locks up quite a bit before the hammer drops. If the hand is rubbing on the side of the teeth, then I would guess the way to fix that is to clean (stone) the teeth or the hand? If that's the case, I will let someone more knowledgeable than me handle that.

As to the warranty, I believe Smith would void it because several pieces inside have been stoned smooth. I shot the gun quite a bit before we tackled this to make sure any problems should show up before I took a chance and voided the warranty. I don't have a problem with paying a local smith I know to do this job. He excels in smith revolvers and I probably will let him time this one a little better.

I called S&W and they told me that it is normal for a revolver cylinder to lock up before the hammer is fully cycled back. I explained that this one locks up quite a bit before and the last 1/8" or so of trigger pull is very rough and gritty making slow fire hard to do good and they told me to keep firing it and it should work in. I've handled quite a few smith revolvers and have not had one lock up like this. Truth is, you would only notice this in slow fire where you are shooting for accuracy. There is no smooth break because of the roughness.

Thanks again.

John

 

[Old Fuff]

I will say that stoning internal lockwork is seldom a good idea, and has ruined far more revolvers then it’s helped. I would strongly advise that you don’t touch the ratchet teeth because again it is likely that you’ll get into more trouble then you’ll get out of.

As for the warrantee. If you send in the gun they will quickly notice what’s been done. If the trigger pull roughness is being caused by something you and/or your friend did then obviously they are not obligated to fix it for free. But if it is a problem that pre-existed before the revolver was worked on, and is being caused by something that goes back to when the revolver was assembled in the first place, they are far more likely to fix it.

Apparently your friend did do something to the hand, and maybe the slot in the frame it moves through. If he didn’t get carried away when it came to working on the slot in the frame (which is generally something you don’t do) they might decide to replace the hand (that is relatively inexpensive) and fit a new hand to correctly interface with the ratchet teeth. After all, they do want to keep you as a happy customer, and if the “fixing” doesn’t get too involved it’s a good public relations move.

I would hope that by now you might be questioning the actual knowledge and skill that your friend really has. It appears to me that he has addressed everything except what really needs to be corrected. Working on the ratchet teeth takes skill and experience, and mistakes are easy to make.

Smith & Wesson does not make a selection of extra-long or wide hands. At one time they made an extra-thick hand so that the timing could be corrected in a revolver that had a worn hand slot. While I’m not sure if they still make them or not, I don’t believe they offer them for sale as a spare part. In any case one of the older hands wouldn’t work in your new model 27.

It’s up to you of course, but given what the gun cost, and the potential of amateur fiddling and fooling around that has been described so far to make things worse; I would return the gun to S&W even if I had to pay for the work, and charge the expense off as a learning experience.

 

[jtmo3]

Thanks again. The only thing stoned was a few pieces (rebound slide and mating surfaces, etc) and the frame (where those surfaces touch). Nothing was done to the hammer sear or trigger critical points. All I was after was to get rid of any burrs. Nothing damaging was done. The stoning on the window amounted to about 3 light swipes to get rid of any burrs. It wasn't my friend who did or didn't do anything wrong. He sees what the issue is and explained to me that the hand or the teeth would need to be worked to correct the timing. Both of us agreed that we shouldn't tackle the problem because we don't have the tools to correctly do it. Nothing was stoned on the hand.

From my conversation with S&W, I would think they would feel the gun was within factory specs, and it might be. I want it better than it is and am willing to do what is necessary. But like you said, I'm not willing to do anything at this point, that will damage the gun. Up till now, the stoning was minor to remove burrs and rough spots. That has been done well, the gun functions fine with a nice smooth trigger until the last 1/8" or so. That's what I'm after. I will not attempt any critical point stoning or stoning on the teeth. That I'm not willing to do but I will/would let a gunsmith that I know and trust do it. That appears to be my next step.

Thanks again for the help.

John

I called S&W and asked them about different sized hands and they told me that yes, they do make different sized hands. Brownells sells an oversized hand from s&w.

 

[Old Fuff]

Brownells sells an oversized hand from s&w.

Indeed they do, but if it's the one I'm thinking of it isn't a S&W part, but rather an aftermarket product.

I wish you luck, as I can't do much more...

 

[rcmodel]

and they told me to keep firing it and it should work in.

See last sentence, post #3.

rc

 

[jtmo3]

10-4. Won't be a problem shooting it a bunch!!! I've put about 1500 rounds through it with little change.

I did talk to a gunsmith at Brownells and he said it sounds to him like the hand is just slightly wide. He said to see if that's the problem, loosen or remove the sideplate screws and try it again. If the problem goes away, I found out for sure the hand is the issue. We did that and the problem was not there.

OK, I guess I'll have to force myself to go shoot it some more. Thanks again guys.

John

 

[Old Fuff]

You can thin the hand, but then the cylinder may not carry up (fully rotate from one chamber to the next). The reason you aren't getting a problem with the loosened sideplate is because the hand is no longer rubbing on the side of the ratchet tooth.