GP100 problem

P

P5 Guy

New member
A fellow shooter had a problem with his new GP100. After about 50 to 60 rounds the cylinder started to get hard to turn with a DA pull and hard to cock SA. After cleaning out under the star of the ejecter all was right with DA shooting for another 50 or so rounds and it started to get hard to cock.
I can shoot 100s of rounds through mine with out any trouble. What is wrong with his? Why is it getting dirty so quick?
Shooting 38 Special in his is worse than Magnums but it still happens. Thanks for your thoughts on this matter.
 
Cylinder Binding Problem - Search

Had this problem. If it is a new gun, send it back to Ruger. What came back was a refined, dehorned revolver with a trigger job that drives nails with .38 and bolts with .357. Remember, it's a lifetime warranty. I couldn't be happier with the one I sent in relative to the one I got back. JMTC or just my .02!
 
It's possible he isn't ejecting the empties properly.
One reason for getting grit and burned powder particles under the ejector is not holding the barrel up as you vigorously push the ejector.

If you hold the barrel more horizontally and push the ejector rod easily, the cases tend to drop more crud behind the ejector.

I recommend giving the rear of the cylinder under the ejector and the underside of the ejector itself a VIGOROUS scrubbing with a dry toothbrush.
Grit tends to stick to the area and when the gun is fired, the grit gets slightly embedded and is hard to get off.

Give it a scrubbing, and some of the grit may not be removed.
After a few rounds the cylinder starts to bind again.
 
I didn't pay very close attention to that. Next time I'll watch closer.
I use a brass wire brush to clean under the star on my revolvers, maybe I'll get him to try that.
Thanks for the info, P5
 
Gp100

Dear Shooter:
I take it that after shooting for a while your cylinder gets hard to trun? Correct?
If so I would look at the barrel/cylinder gap.
Years ago Ruger had a problem with barrel/frame/cylinder/cylinder gap alignment. I wrote Bill Ruger (years ago) about the problem and much to my suprise Mr. Ruger wrote me a personal lett which I still have, that he took to the toolroom floor!
The problem they had was that the barrel was out of line with the top-strap of the frame and the bbl. cyl. gap would be .002 on the left side and .012, or more on the right!
In my shop I would unscrew the bbl, take it back it one thread, and restore the cyl. gap to from .002 to '005. (divide 1000 by the thread pitch and get the amount to turn back one thread) and correct that.
But - I tended to be too precise and got some cylinder gaps (after correcting cylinder play) too close - like .001!!
This may be happening to your excellent GP100! Your bbl/cyl. gap hay be too close - I like to see them about.004! If the're tighter the powder fouling/bullet jacket material may be accumulating and causing it to bind up. You, yourself may carefully (if this is the trouble) stone off the bbl. till you have from .002 to '004 gap.
By the way - much of the "muzzle blast" comes NOT from the muzzle but from that bbl. cyl gap!
Try this carefully. Harry B.
 
sp101 prob.

I have the same problem with my sp as you do with your GP; I shoot a few rounds and it locks up tighter than dicks hat band.:mad: so I guess it will go back to the factory soon.
 
Guys, listen to Harry. All you need is a common automotive feeler gauge. If you can't slide a 0.003" easily between the back of the barrel and the cylinder face, you are courting nuisance problems. I have a Dan Wesson that I tried all manner of cylinder gap sizes with just because I can adjust it. 0.002" just wouldn't let me shoot a lot. 0.004" was just great. 0.006" seemed to let more lead splatter on the cylinder face. 0.004" is, in the words of Goldilocks, "just right".

One other thing to check: Is the biggest problem occurring with very light .38 loads? If so, check whether the sides of the cases are getting smoked? If so, you may be loaded too light or running a low velocity load with a powder that is too slow for it. In either case the pressure is too low and the cases either don't expand fully into the chamber or don't remain expanded until the bullet is out of the tube. This allows pressure to push smoke rearward and it will cake up around the corners of the chamber where the ejector seats. This will prevent the ejector from going completely back into place. Beefing the loads up or using a faster powder to get your low velocity target loads will cure it.

Nick
 
If they are very dirty it is due to incomplete combustion. This is common when using light loads of a powder that is too slow for the job. The powder requires a certain amount of pressure to burn fast enough to get done burning before the bullet leaves the tube. A light load of slow powder raises the pressure slowly enough that the bullet starts to move before an adequate start pressure (for the powder) is reached. Once the bullet is moving, the space the propellant gas has to fill keeps growing and a slow powder never catches up to that growing space before the bullet leaves a pistol-length barrel. The same load will always be even dirtier in a short barrel.

For a club load that will be fired in everything from snubbies to 1911's to long-barrel .357's, you want about the fastest powder you can get. Even old target standbys like Bullseye and W231 will be on the slow side for snubbies.

Listed below are some loads that launch a 148 grain lead wadcutter at 750 fps in a six inch barrel and burn 100% in both 2" and 6" barrels. 1.145" OAL (case length; bullet seated flush with case mouth).

Hodgdon Clays: 2.4 grains (Note: This is Clays, and not Universal Clays)

Norma R1: 2.5 grains

Vihtavuori N310: 2.3 grains

Alliance Red Dot: 2.4 grains

Accurate Solo 1000: 2.5 grains (Note: This is one exception, burning only 97% in 2" tube)

Compare these to the old standby wadcutter target load of 2.7 grains of Bullseye, which burns 79% in a 2" revolver, 89% in a 5" 1911, and 92% in a 6" revolver, and you can see why they are cleaner. You might suggest these to your club's loader, or try them yourself for comparison. See if anyone else has their guns gumming up from the existing load?

Nick
 
gp100 problem

Gentlemen:
Hey! Nick!, on the Dan Wesson I think they send a .006 guage with it. However, there is a problem with the Dan Wesson.
When I had mine (357) and set the bbl. and fired roughly two cylinder fulls plinking the bbl. got loose!!!
So, I deduced that heat had elongated the bbl in the shroud. So after firing several rounds I'd use their tool and quickly set up that nut very tight - viola! no more trouble.
However, going up a staircase with my Dan Wesson I sometimes - not always, noted that the next round would catch the rim of the case on the bevel inside and not rotate.
I never liked a clockwise rotating revolver after that really. Some have made improvements in this regard and now are probably O.K.
Harry B.
 
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