I was shooting some Remington .357s (cant remember the weight but I think it was 158) out of my 6inch and 3inch gp100's and experienced some lockups on the 6inch, the 3inch didn't lock up but didn't seem to like the remingtons either. I checked both revolvers out and they didn't have any excessive build up or anything that I could see that would cause a problem and I looked at the Remington casings and didn't notice anything unusual. I gave them a moment to cool down then tried both of them with wwb .38+p and they worked like a dream (as usual).

I typically don't shoot .357s too often (although I do shoot .44mag out of a srh a lot..go figure), just wanted to know if their is a particular brand/weight I should stick to for the gp100s?

thanks,
tx40d

I had the same problem with a GP100 6", blue model. Seems the cylinder contacted the lower front of the frame as it heated up. Check for marks on the front edge of the cylinder. Easy fix with a polishing disc on the dremel or send it back to Ruger, they will fix it in time.

It doesn't appear to be an ammo problem since it worked fine in your 3" gun. I have a GP100 and have never had a problem with any brand including Remington ammo. I would suggest that you do a thorough cleaning of your cylinder face and your forcing cone. Take a measurement of your barrel/cylinder gap to determine if it is within spec. If it is too tight, you should contact Ruger for adjustment. As you are apparently aware firing a large quantity of hot loads can generate a lot of heat which would contribute to your problem.

My cylinder locked and wouldn't turn. the cause was unburnt powder under the ejector. Doesn't seem possible, but a couple of granules of powder residue under that thing will bind the cylinder. Answer is to be sure the gun is pointed upwards when ejecting empties so the powder won't collect there.

My neighbor purchased a new 6" GP100 in .22 LR. He started experiencing the same problem you describe. He called Ruger and they told him to send it in which he did. When he got it back, they were rather vague as to what the problem was other than saying that they replaced the pawl. Works fine now.

Thanks for the replies. I looked at the cylinder and it looks ok (no marks). Gave it another cleaning and tested with snap-caps, worked fine. I will give it another go at the range. I have a feeling you guys are right and it was running a little/lot hot and was dirty from the .38s, I'll report back afterwards.

tx40d

Keep out any excess oils from under the ejection star. This will lead to the collections of fouling upon it. Make this area quite clean at all times and see if this helps. My GP100 6" SS will do this in firing many rounds. The powder gets under the star and jams it.