.22 GP100 cylinder firing pin marks

Got the new 4" GP in .22 last week and have put a few hundred rounds through it so far. It has had one FTF and that was ammo as I rotated the round and hit it in 3 different areas. I'm getting a bit worried though that the firing pin is coming out too far and damaging the cylinder.

Here is a picture of when the cylinder was new.



And here is a picture now.



There is an obvious firing pin mark at the top of each chamber. What are your thoughts? It's been dry fired less than 5-6 times, plus it's supposed to be safe to dry fire. I really want to shoot it this weekend at my clubs plate match, but don't want to damage it. I really would like to keep this cylinder as the machining on the ratchet looks to be very nice even under magnification. May have to file the ejector a bit though as you can see little curls at the points.

What are your opinions?

Stop dry firing it period. Its not good todry fire any rimfire, I don't care what the manufacturers say. It leaves the mark as you noted. So don't do it and everything will be fine. There are .22 snap caps if you must do it.

I'm sure it's safe to fire rounds without causing further damage. But it looks like yours is not safe to dry fire. My new GP 100 10 shot has been dry fired many times and I don't have any issues with cylinder damage, but I had to modify my firing pin to get reliable ignition with several brands of ammo.

I have about a dozen rim-fire revolvers and have been lucky to have no damage from dry firing, but if I did I would stop dry firing.

I'd be concerned about the hardness of your cylinder with it indenting like that!

Suggest you contact Ruger and ask, as does not seem normal.

By dry firing I didn't mean all chamber 5-6 times, I literally meant 5-6 times so some chambers haven't been dry fired on at all, yet still have the mark. I'm not a fan of dry firing rimfires even if it's supposed to be OK. I think I'm going to go with Steelshooters advice on calling Ruger. Dry firing will happen on occasion testing out the trigger and I don't want to make the problem worse.

Maybe it's just an optical illusion, and I don't have a GP100 in .22lr, but those marks look really big to be made by a firing pin. It's almost like the pin is being transferred onto the cylinder through the brass. Are those marks as deep as they look or are they halos, can you feel them with a pick?

dingode.... although photos are capable of illusion, firing pin indent in rim counterbores of cylinder appear to be steel-on-steel, not result of repeated dry firing on cartridge case. I would measure pin protrusion before trimming. Reliable .22 rimfire ignition requires an unusually strong strike. If the counterbores which shield against the rupture of a hollow rim are shallow, a firing pin within spec may INDENT an EMPTY CHAMBER. If so, as members of Rugerforum advise, DRY FIRE must be avoided. My ancient S&W K-22 has been dry fired on fired cases a rather staggering number of times without incident. I much prefer to dry fire .22s on fired brass, rotating the case to cushion multiple strikes. The K-22 firing pin does not reach the rim counterbore.

In the event PROTRUSION is excessive, Ruger Customer Service may be the preferred remedy. Milling burrs on the extractor can be addressed at the same time.
David Bradshaw

I called Ruger and they Emailed me a shipping label and it's on it's way to them. The indents are visible to the naked eye and you can feel them. The gun has only been dry fired 5-6 times total, not 5-6 times on each chamber so it's been very limited and usually by accident when checking the DA trigger pull. Snapcaps are on order to fix this issue when I get it back. It would seem the dents are being transferred through the brass into the cylinder, so maybe it's not hard enough steel as was suggested earlier.

I also forgot to mention in my post here that some of the cases had a bulge under the rim after being fired. The bulge went around about half the circumference. I also passed that info on to Ruger along with that it also had intermittent sticky/hard extraction. I'll see if I can get a pic to post.

I included a note with it to see if they could also look at a few blemishes it shipped from the factory with. A sharp edge on the trigger guard, a scrape on the crane that looks like they let the edge of the buffing wheel hit it, and the curly burrs on the extractor points.

I have faith in Ruger to fix anything that's wrong. I sent them a MKI pistol that was rusty, scratched, and almost non-functional for a refurb/reblue and it came back looking and working like new. I think they replaced every spring and pin in the gun. I asked them to D&T it for a rail while they were at it and they even did that for free since I bought the rail from them. Their customer service is outstanding. I'll post an update when I get the gun back, which I figure will be next week sometime.

You caused me to look at mine. Mine has never been dry fired by me, nor will it ever. And none of mine will ever be dry fired, regardless of what Ruger or the internet folks say is okay.

But it does have firing pin marks, which must've been caused during the functioning/dry firing at the factory.

I also looked at the firing pin protrusion. I do not believe it is possible to have the firing pin dent the priming rim, and leave a mark on the cylinder on the other side of the rim.






Furthermore,,,This caused me to fire a couple rounds and then inspect the brass. My inspection showed no sign of the firing pin punching thru the brass hard enough with enough residual energy to cause a dent in the cylinder. But...The brass did take the print of the little divot in the cylinder.



WAYNO.

Wayno, your cylinder looks like deeper dents than mine even. Were they there when you bought the gun? I can't think Ruger dry fired it that much at the factory. I see you extractor points have the same little curly burrs mine does, do they cause you any issues? I'll let you know what Ruger say's or does about mine.

Here are a couple of photos of the bulged cases, I'm thinking the extractor may be a hair overcut on my gun. I'm not too worried about it I don't think the head will separate or anything. But I did make Ruger aware of it and sent in some brass for them to look at.

Win. 36gr



Mini-mag

dingode said:

Wayno, your cylinder looks like deeper dents than mine even. Were they there when you bought the gun? I can't think Ruger dry fired it that much at the factory. I see you extractor points have the same little curly burrs mine does, do they cause you any issues? I'll let you know what Ruger say's or does about mine.

Here are a couple of photos of the bulged cases, I'm thinking the extractor may be a hair overcut on my gun. I'm not too worried about it I don't think the head will separate or anything. But I did make Ruger aware of it and sent in some brass for them to look at.

Win. 36gr



Mini-mag

Click to expand...

I never looked for these dents until you pointed yours out. And you say they look deeper than yours. I'd say it is an optical illusion, as they are so shallow I can barely feel them with a dentist pick.

These little marks are a non issue to me. Dry firing does that to cylinders, and that's why I never dry fire. Your rims not fully seating, however, would be a huge concern to me. I've shot the gun a bit, and I've never noticed the rims not seating home on mine. I will now look for the little burrs on the extractor. If I have them, i will clean them out.

Did Rugers of old leave the line with curly cutter burrs on the cylinder? No pride in workmanship!
But then CNC machines have no feelings.

Mus408 said:

Did Rugers of old leave the line with curly cutter burrs on the cylinder? No pride in workmanship!
But then CNC machines have no feelings.

Click to expand...

I agree, these burrs are not acceptable. But ya know what? If I had not taken these close ups, I never would have seen them. Makes me wonder how many other burrs I was pleasantly ignorant of.

Update...

Spent a little time straightening out the burrs on the ejector star. They were so nearly microscopic to the naked eye and my trifocals, I touched them with a little pick, the burrs straightened out and broke off. A few passes with a wire brush, and the burrs are completely gone. The wire brush also minimized the firing pin marks, which are very close to nothing. Again, without the close up photography, I never would have noticed either the burrs or the firing pin marks.

I never noticed the burrs on mine either until I took a photo through a magnifying glass. Hopefully, the firing pin indents on my cylinder will be nothing to worry about, I even offered to Email Ruger pictures so I wouldn't have to mail it in, they send no need for pics, just send it.

Maybe they should just mill out the cylinder like Uberti does on their 12 shot revolver, they must use extended firing pins.

I modified my GP 100 10 shot firing pin to get more reliable ignition with several brands of ammo, I can now use a lighter hammer spring.
I made it look more like my S&W firing pin. The fired brass above shows the difference.
I hear Ruger won't sell you a new pin in case you mess it up, so it is risky to do. But in my case it was worth it.

If I had problems with ignition I was going to try your modified firing pin shape. We have a machinist where I work but out lathe isn't the best. We also have a machine shop we work with on a daily basis, so I would have probably had them do it. But my gun has been 100%, and hopefully, it'll stay that way when it comes back from service,

The picture you posted of the 12 round cylinder has piqued my interest, off to google it.

You don't need a lathe for this, you can just chuck it in a drill motor and take
a hand stone to it.
Only issue I had was removing the pin's retainer....it was tight and had signs of
locktite...took a bit of heat and had to make a small tool to engage the holes.
Dave

Took this revolver to the range a couple days ago. Fired a couple hundred more rounds. No additional evidence of firing pin marks, so I believe the existing marks were from dry firing at the factory, and very superficial.

Now the other concern is, I did not shoot this gun very well. I had a very bad batch of Mini Mags, with poor round to round consistency. That, and I was just not shooting very well. I'm not yet ready to blame the gun. I will have to wring this gun out another time.

WAYNO.

Ruger got my gun last Thursday, but I haven't heard back from them yet. I'll give them a ring on Friday if they haven't contacted me by then.

Accuracy kind of has me worried too. For now, I'm going to chock it to my inexperience at shooting revolvers and that god awful front fiber optic. Something about that sight just doesn't work for me. I have FO sights on my S&W Victory (front and rear) and XDm 5.25 competition (front only) and I shoot those just fine. I think both are brighter than the GP's. Maybe I'll put a new tube in and see if that helps. I plan on going to a red dot soon, so it may not matter.

When it comes back, I plan on having some of the wheel gun lovers at my club put some rounds through it and see what they think. I looked at the crown and forcing cone under magnification and they both look issue free. It's not spitting out lead or anything either, so I think cylinder alignment and timing is good. At first glance, the rifling looked shallower than my other Ruger .22's but I didn't do a comparison to double check it. I have a friend that is a bench rest shooter and along with all the other sweet toy's that hobby requires, he has a nice borescope. He looked at the rifling in my SR-556 when I got it and said Ruger did an awesome job and that it looked perfect. I'll have him inspect the GP when I get it back.