GP100 hard trigger pull

[baryon]

Hi Guys,

Posting after a long time here. I bought a rarely used GP100. Shoots fine in SA. But in DA the trigger weight feels very hard on 1 particular cylinder. The rest 5 feels around 12 lbs.

Any ideas how to troubleshoot this?

 

[tacklebury]

Look at the serrations on the rear of the cylinder, one might be peened down from being dropped or something. Might just have some gunk also. Just a thought.

 

[Jimbo357mag]

First a thorough cleaning with a de-greaser like 'Gun Scrubber' or soak and work the action in a container of kerosene. Be sure to clean under the ejector star. Be sure the cylinder spins freely with the crane open. Sometimes gunk can build up on the shaft the cylinder spins on. Oil with a good gun oil like 'Rem Oil' and check the action.

Is there any binding of the cylinder and the barrel? (B/C gap). Is there any scrapping of the ratchet teeth or anything on the backplate? Check the teeth on the ratchet carefully, any nicks, burs, dents? Check the notches on the cylinder. Check the lock-up after pulling the trigger in double-action. Hold the trigger all the way back and wiggle the cylinder back and forth. There should be a tiny amount of play.

I can't think of anything else.

edit to add: Maybe there is one chamber where the cartridge isn't seating all the way. Does it exhibit this problem with the gun empty or only when you are firing it?

...Jimbo

 

[GP100man]

Nuttin to add except look real close at the ratchets under magnification if possible , It could be such a suttle difference that it only pushes the hand over in the window & causes a hard spot .

 

[baryon]

edit to add: Maybe there is one chamber where the cartridge isn't seating all the way. Does it exhibit this problem with the gun empty or only when you are firing it?

...Jimbo

It happens even when I dry-fire all 6 cylinders.

 

[baryon]

Look at the serrations on the rear of the cylinder, one might be peened down from being dropped or something. Might just have some gunk also. Just a thought.

Do you mean the 6 T shaped notchs(?)

 

[Jimbo357mag]

Look at the serrations on the rear of the cylinder, one might be peened down from being dropped or something. Might just have some gunk also. Just a thought.

Do you mean the 6 T shaped notchs(?)

I am sure he means the teeth on the ejector. The pawl pushes up on the teeth to turn the cylinder. If one of the teeth is mis-shapen it will cause a bind when trying to rotate the cylinder. I once had a bad tooth on the ejector of my SP that had to be dressed with a small file to repair a bad angle.

...Jimbo

 

[tacklebury]

Yep as Jimbo said. I have an H&R double action which does what you're describing on 2 of the cylinders and upon inspection, 2 of the teeth were bent over slightly, catching the pawl.

 

[baryon]

OK. Upon closer inspection of the star(?) in the ejector, it appears one of the teeth appears very rough. Now, how do I remove this to do a little polishing?

 

[Jimbo357mag]

I'm no expert. The crane and cylinder comes off the gun easily. To get the cylinder and ejector apart is somewhat difficult and putting it back together is even worse. Perhaps you can put the whole cylinder assembly in a padded vice and work on it that way. Small jewelers' files or small pieces of wood with very, very fine sandpaper can dress a tooth on the ejector.

...Jimbo

 

[nn]

OK. Upon closer inspection of the star(?) in the ejector, it appears one of the teeth appears very rough. Now, how do I remove this to do a little polishing?

Nice job finding that issue, I was about to say that was probably the issue.
Probably can fix it carefully with out taking it apart.

 

[GP100man]

I fold 600 over a pocket screw driver & work litely as the screw driver will punch thru easily .

 

[baryon]

Thanks guys, I took a 400 sandpaper and tried to polish it, but looks like it requires a metal file to actually reach it.