I’m not to sure where to post this, here, or gunsmithing. Lots of knowledgeable people on the older revolvers so I will ask it here.
1915 M&P-
The dome on this pin (trigger pin) is rubbing on the cylinder when it’s open and locked in it’s detent. As you can see in the picture not a lot, but definitely rubbing. I can feel it dragging on the cylinder.
Here is the question, can I tap this pin with a punch to flatten it. Leaving the side plate on for support?
Any other suggestions appreciated.

No. It is a threaded stud, not a pin.

Can you SEE it touching? Old guns often have a really sticky varnish in the guts formed by decades old oil. That goop on the barrel of a yoke can really retard cylinder rotation. Pull the cylinder and clean the yoke and the center hole in the cylinder.
If it is clean and you still feel it rubbing you may have a bent yoke. It is easy to straighten if you have a yoke alignment tool and know how. Otherwise, have someone else do it.

__________________
Regards,
Lee Jarrett

Man, with the condition I see on that over 100 YO M&P, I'd leave it the heck alone. If I even contemplated putting a punch on it, I'd slap myself!

__________________
Guy
SWHF #474 SWCA LM#2629

Thanks for the quick reply.
“Can you SEE it touching?”. Yes, but it is just barely. I feel drag.
If just lift the cylinder a very small amount it spins freely without touching.
I took it apart cleaned the dried goop out and re-oiled it, I will take the cylinder out and have another go at it.
Thanks again for the your thoughts.
Frank

😳 I know, that’s why I asked.😁 didn’t want to do it.

If it bothers you or the operation of the gun, chances are the best fix is to remove the sideplate, gut the mechanics, and remove the stud. You will need a spanner wrench or fashion a slotted screwdriver and turn the stud out of the frame. The head would need to be reworked to "soften the dome and then it could be re-blued using one of Brownell's bluing agents. If you boil the stud in water, remove it and it will flash dry, then apply the blue to the dome. Repeat as often as needed to get the depth of blue you want. It will be quite a durable finish and should solve the problem. While you have the gun apart is the time to thoroughly clean it and lubricate before reassembly.

If you do not want to tackle it yourself, a good gunsmith can do the work for you.

__________________
Gary
SWCA 2515

As handejector posted, the most likely cause is the yoke shaft slightly out of alignment: treat the cause not the symptom.

Without a yoke alignment tool you can still check the yoke barrel for straightness:

open cyl and remove yoke from gun, remove cyl and reinstall the yoke and the retaining screw.

now place something straight, long, and snug fitting into the yoke barrel (some pencils will work well).

If the barrel is not straight, the long pencil will accentuate the misalignment enough so you can see it. It will slant down towards the frame when viewed from the bottom of the gun.

If so, have the yoke barrel aligned by someone or buy the tool. The yoke is not hard to straighten. Few yoke barrels are "PERFECTLY" straight. Shortly after your gun was produced, that stud was polished flat to avoid the problem.

(If you were lucky it would be slightly out of alignment in the other direction and provide extra space so the cyl didn't rub on the stud.)

If you're still convinced the yoke barrel is perfectly straight:

I've heard of some that will remove the side plate and parts and screw the threaded stud out 1/8th of a turn. Usually still very tight. You'd need the proper spanner wrench (slotted screwdriver). Confirmed that the cyl clears the domed tip, that there's no binding of parts, and that the side plate still fits on flush to the frame.

__________________
Jim
S&WCA #819

Thanks to everyone for the clear and concise answers. I think I will buy the tool and check it out and fix it.
It a minor annoyance, the revolver shoots great and seems to work fine other than this little rubbing on that pin. When I took it apart and cleaned it I didn’t take the cylinder apart. So that’s what i will do first. Then go from there.
Thanks again for the information. 👍

It'll be good to clean it but even if that makes it spin smoother, the evidence is there that it is rubbing the tip of the stud.

__________________
Jim
S&WCA #819

Ordered the Brownells alignment tool. When it gets here I’ll take the cylinder apart, clean it, check the alignment, and fix if necessary….I hope. 😎
Will report back with my success, I hope. 😁

Got my $60 cylinder alignment tool, so with little or no trepidation I dove in. First off, yes, I am a kitchen counter “gunsmith”. The big hammer and punch is for Guy. 😁 Better lighting, cooler, and a great stereo to drown out my cursing. 😁
Got my 19-3 as a test model, since I wouldn’t have to take the the ejector rod off and it’s a little rough.



All went well. The tool actually worked very well on the M19-3. It’s as smooth as silk now. My M&P was perfect, according to the tool.
Cleaned everything up and put it back together. I guess it’s just a “tall pin”. It barely touches the cylinder in a couple of spots. I can live with it. It is a beautiful revolver.
Thanks to all for the help and information on this project, it’s greatly appreciated.

Shucks! I was sorta lookin' forward to a mutilation video...jes sayin'

__________________
Guy
SWHF #474 SWCA LM#2629