revolver rotating slow on 1 chamber

[throttletony]

Hi all -
If this is better suited in "gunsmithing", mods can please move it.

I have a Ruger GP100 Match Champion that I love.
The other day at the range, after about 150 rounds of 38 spl and 357 magnums, the trigger started dragging and was having trouble rotating the cylinder, but only on one specific chamber the others rotated smoothly like normal (the trigger was just extra heavy, not necessarily gritty). I still fired about 12 more rounds, and it was only tough when that one chamber would come around, not on all cylinders. With an empty cylinder, I dryfired it about 30 times and the problem went away. The problem did not return during the rest of the outing.

I should have inspected it more closely. I'm thinking it was probably buildup on the front of the cylinder, on one specific chamber that was scraping the outside/leadin-edge of the forcing cone. (Ruger revolvers also have the transfer bar safety, I wonder if that was dragging inside.. but I found no debris that would interfere with that or the pawl or cylinder latch)

After a good cleaning it's silky smooth again, but I'm not sure what the problem was. I welcome any feedback.

Any other ideas? or things to look out for?

 

[indiucky]

I had a 629 Smith and Wesson do that one time...I sent it to Smith and they replaced the barrel....The barrel had "twisted" in the frame from recoil and had set one chamber out of time...

 

[throttletony]

I had a 629 Smith and Wesson do that one time...I sent it to Smith and they replaced the barrel....The barrel had "twisted" in the frame from recoil and had set one chamber out of time...

wow, that's nuts.
629 is .44 mag, right? think a .357 mag could do the same thing??

edit to add: after the roughness worked out, nothing seemed out of time (no extra copper shavings, etc)
Lock-up still feels tight all around (with all diff chambers).

I'm not a revolversmith at all, just very familiar with Ruger internals.

 

[BehindBlueI's]

Look for crumbs of powder under the extractor star. Nearly every issue with cylinder drag I've experienced with a Ruger has been to build up of gunk there.

 

[Leadeye]

^ This.

I gave up using some powders because of this problem.

 

[Leo]

Use a feeler gauge between the barrel and cylinder when the revolver is clean. They should all be the same. I have seen minor roughness on the front of stainless cylinders that needed minor stoning and polishing. Once that is done, the problem never shows again, even when the handgun is dirty.

 

[Old Dog]

If you were using .38 & .357 in the same range session you could be dealing with something as simple as your .38 loads leaving powder or lead/copper build up in a chamber that is a little tight or a little shallow. Since cleaning took care of it I would move on until it shows up again. Did the binding occur on .357s after firing .38s?

 

[throttletony]

If you were using .38 & .357 in the same range session you could be dealing with something as simple as your .38 loads leaving powder or lead/copper build up in a chamber that is a little tight or a little shallow. Since cleaning took care of it I would move on until it shows up again. Did the binding occur on .357s after firing .38s?

This had occurred to me also... after I left the range.
If I remember correctly it happened with 38safter shooting other 38s.

 

[throttletony]

Use a feeler gauge between the barrel and cylinder when the revolver is clean. They should all be the same. I have seen minor roughness on the front of stainless cylinders that needed minor stoning and polishing. Once that is done, the problem never shows again, even when the handgun is dirty.

This is a good idea. I should have done this before cleaning it.
I measured the cylinder gap when the gun was new, and it was .004. I'll re-measure it now to see if it has tightened/loosened.
I think Ruger and S&W specs say that between .004-.008 is "ideal", and QC will still pass .010.
If anyone knows for sure, please correct me.