9MM Super GP100 trigger sticks rearward

[IHAVEGAS]

If I put in a reduced power trigger return spring (McCarbo) the following happens:

During dry fire all is good.

With live rounds the trigger sticks fully back about 1 time in 5, a combination of pushing forward on the trigger and twisting the cylinder one way and the other eventually allows the trigger to return forward.

 

Would greatly prefer to run the reduced power return spring. Any ideas? 

[Fishbreath]

You'd think I'd be better equipped to help with this, after a year and a half being The Super GP100 Guy, but I confess I haven't seen this issue myself (running the lightest return spring that came in the Wolff pack).

 

How's the fit between the hammer and the transfer bar? Is it possible the shock from the firing pin rebounding is binding things up? Maybe polishing the transfer bar and hammer face will help. I also turned up an old post on another about a regular GP100 that was sensitive to pawl/hand length, and the hand would slip up over the ratchet in some way (no pictures, unfortunately).

 

rugerforum.net may also be able to help.

[IHAVEGAS]

Thanks. Will look. It does seem a weird problem. 

 

This gun has been sent back to Ruger already to have a new pawl installed to fix a timing issue (not relevant likely, just for what it is worth). My gut makes me think they pushed the design/precision limits a bit too close to the edge when they went to 8 shots. 

[Fishbreath]

35 minutes ago, IHAVEGAS said:

a timing issue

 

What was it, out of curiosity?

 

Possible, on the 8-round thing. I didn't realize until just now that Ruger is pretty new at the 8-round revolver game. As far as I know, this is the first 8-shooter built on the GP100/Super Redhawk platform, and I don't think the 8-shot non-super Redhawk beat it into production by very much.

[IHAVEGAS]

Pardon my terminology.

The thingy that comes up to mate with the slots in the cylinder was not dropping back down soon enough on one chamber, so the cylinder could not rotate. Again with the 8 shot, getting the star just right for all 8, plus getting the cylinder slots just right for all 8, plus getting the pawl timing at a happy neutral, plus getting the thingy timing at a happy neutral, might be a challenge for the design.  

You may have noticed by this point that I am not a revolver smith. 

[Cherokeewind]

Try dry firing with empty cases in the chambers just to see if the cases have anything to do with the problem.

[pskys2]

I had a GP100, not Super, and when I first put in the light rebound spring it hung up.  I had already polished up the mating surfaces so I just dry fired it a hundred or so times and it got better.  Then after live firing a few hundred it smoothed out and quit hanging up.

 

Might have to polish a few things, but I'd just run it in dry fire for a bit.  Oh and oil all of the contact surfaces in the action.

[CtYankee]

I had a similar problem with a GP100 MC 10mm. I had installed an 8# trigger spring and had a periodic failure to reset. I sent it back to Ruger with a list of things I thought that they should fix. It worked much better, but before I put the 8# spring back in (never send your gun to Ruger with non-stock parts) I took the gun apart and polished all interacting surfaces, especially the trigger plunger and the cylinder latch. With a 12# hammer and #8 lb. trigger spring I have an 8# DA trigger pull. Polishing parts seemed to be the key, for me anyways.

[IHAVEGAS]

All of the above input, and any forthcoming input, is appreciated. Will post if/when I get things working, life is getting in the way of gun fiddling at the moment.

[IHAVEGAS]

On 5/3/2021 at 1:21 PM, Cherokeewind said:

Try dry firing with empty cases in the chambers just to see if the cases have anything to do with the problem.

 

When I read that suggestion I thought no way, then I thought well maybe, regardless, the problem is not there with an empty chambers but it is there with fired cases in a moon clip inserted in the gun. 

 

Thanks. 

[Fishbreath]

Now that's a fascinating finding. I wonder if maybe it's a pawl/ratchet fit issue, then? That's about the only thing I can think of that would be affected by having empties in the cylinder (thus constraining the cylinder's forward/back position more than if it didn't have anything in it).

 

With nothing in the cylinder, do you run into problems if you hold the cylinder forward with your fingers? When the trigger sticks, does pushing the cylinder backward as much as possible help?

[Cherokeewind]

I recently had a new hand installed in a M29, dry fired fine but trigger would sometimes jam preventing firing with live rounds.

 

Noticed very small marks on the rims of some cases and discovered that the marks were being caused by the tip of the new hand, actually the outside edge of the top of the hand.

 

The new hand had been fitted by a sorta local refinishing/custom shop and the mechanic-in-training (?) failed to taper the very top of the new hand, leaving a more or less square corner to wedge against the rim of the cartridge which would be the next one to come up to be fired.

 

I discovered the problem while diagnosing with empty cases. 

 

Simple fix but never would have happened if the shop knew what they were doing.  Needless to say, I don't go there any more. 

Edited May 24, 2021 by Cherokeewind
added info.

[IHAVEGAS]

2 hours ago, Fishbreath said:

Now that's a fascinating finding. I wonder if maybe it's a pawl/ratchet fit issue, then? That's about the only thing I can think of that would be affected by having empties in the cylinder (thus constraining the cylinder's forward/back position more than if it didn't have anything in it).

 

 

 Between you and Cherokeewind I think you have fixed the problem for me.

With the hammer removed I still had the issue, noticed it was on two spots of the cylinder only. After several pulls of the trigger (it is easy to get a lot of pulls with no hammer spring) the sticking went from 100% in two spots to maybe 70% and it required less force to pull the trigger forward when it did stick.

Very carefully removed some material from the arched underside of the pawl with the Dremel and a small diameter stone and then polished it. 

Seems ok now, time will tell. Probably just my imagination but the trigger seems smoother throughout (polished a few other points while I had thing apart). 

 

Edited May 24, 2021 by IHAVEGAS

[IHAVEGAS]

Update, last I hope.

 

With the gun 100% together I still had the problem, I have no idea why putting the hammer spring back in made a difference.

 

The two positions of the cylinder where I had issues were positions where the pawl was contacting the star sooner than the other 6 positions. I concluded that by pulling the trigger very slowly and seeing a difference in how far the cylinder rotated versus the timing of the cylinder latch. 

 

I noticed also that the star could be rotated more in the cylinder when the cylinder was empty - the empty brass and moon clip reduce free play which seems to explain why I could get binding of the star/pawl with the spent brass/clip installed but could not get things to bind otherwise

 

Put an angle on the upper left portion of the pawl and polished the heck out of it. Can not get the gun to fail again. 

 

 

[Cherokeewind]

Sounds like good news:)

[IHAVEGAS]

1 hour ago, Cherokeewind said:

Sounds like good news:)

 

It is nice when things start to make sense  . 

 

My best guess on the hammer spring making the problem come back is that the shock of the hammer dropping allowed the pawl to wedge in place a bit worse, that might be baloney but the rest of the problem I think I understand now.