S&W 15-6 Cylinder Over Rotation

[tgallmey]

First time revolver repair. When I pull the trigger hard or cock it fast the cylinder will spin past the chamber. If you spin it by hand it used to lock up but the problem has been getting worse. Obviously I havnt been shooting it since the problem started. Just fiddling with it. Will replacing the cylinder stop with a Power Custom Oversized fix the problem I’m having? I don’t see any obvious damage to the cylinder stop and it’s dropping and popping back up in time like it should. I don’t have any excessive endshake.

 

[JHB]

Take the side plate off and clean the action parts with a good spray cleaner like break clean. Then lube with a light oil on pivot points. you tube has some videos. Watch a few there is the proper way to remove a side plate and then there is Buba's way. Never pry.

 

[Bosshoss]

It is called cylinder skip.
First off take a magnifying glass, unless your eyes are real good.
Look at the notches in the cylinder, and look closely at the bottom of the scallop(lead in) to the notch. You are looking for a raised burr at the bottom of the scallop.
What happens is when cylinder is spun fast in DA or thumbing the hammer back quickly the cylinder stop rides the scallop down to the notch. If there is a burr there the stop hits it and bounces up and over the notch or into the top of the other side of the notch which causes peening(a burr) on the back side of the notch.

DO NOT file these burrs if they are any on the cylinder notches.
I take a hardened dowel that fits the scallop and with the round side of the dowel I tap the burr back down. if the back of notch has a burr I use the flat end of the dowel and tap the burr back down.
If you file the burr down that metal is gone forever.
I have used the dowel to tap some cylinders burrs 3 or 4 times and they are still in service or at least I haven't heard from the owners otherwise.

If notches look OK replace the cylinder stop with a stock one. No need for a oversize stop unless notches are worn way oversize which is very rare.
Check the cylinder stop spring also. Seen lots of them installed wrong and it doesn't have enough tension on the stop as it has a kink in the spring or even a 90 degree bend in it.

The cylinder stop takes a beating in a S&W revolver when shot fast DA. Just a slightly rolled edge or a little wear will cause problems. It is a easy and cheap part to replace as a wear item and should take care of your problem. Just make sure the cylinder notches aren't peened as that can cause cylinder skipping also.
Good luck and keep us posted.