25-2 Problem

[Airedale]

My 25-2 misfires at speed. Slow fire is 100% reliable. When I go to speed, I get misfires. The primers on the misfires are struck on the outer edges. At slowfire, primer strikes are dead center.

The hammer appears to run straight. When cocked, I can wiggle the firing pin very slightly (side to side and up/down).

I put in a new main & rebound spring-no change.

Ideas?

Thanks,

Dave

[Randy Lee]

Greetings,

It sounds like your cylinder stop spring may be anemic or there are burrs building up on the cylinder stop recesses. If the spring is weak, it will not apply enough upward force to lock the cylinder in place as it rotates at hi speed. The cylinder then skips past the locking notches resulting in off center and sometimes off primer hits. Replacement of the cylinder stop as well as the spring may be necessary.

I hope this makes sense as I'm buzzing on caffeine and sugar...

Randy

[Airedale]

Randy,

It makes perfect sense.

I dryfired at speed and the cylinder will pass lock up. I'll disassemble and check it out. The ball appears to be rounded like my 625s & 627s. The spring feels a bit weak.

Thanks,

Dave

[Airedale]

Randy,

Thanks!

I disassembled, cleaned, very lightly stoned the ball. I "stretched" the spring very slightly, and reassembled.

Two moonclips in the pasture as fast as I could go and it runs great.

Thanks,

Dave

[Randy Lee]

Hey Dave,

Glad it worked!

Randy

[Waltermitty]

Keep an eye on it. I experienced the same kind of failures with my 625, and within about 6 months I had to replace the cylinder. The high-speed trigger work will tend to peen both the cylinder and the stop.

[spook]

Walter, this is true, but I have found that the peening stops after a while. It's like cold hammering the notches. I have an old "model of 1988" that has been fired and dry fired millions of times. It has some side to side play, but it is 100% reliable and shoots straight...

Let it go and don't try to stop or repair the peening.

[Randy Lee]

Sometimes in the course of a trigger job, a smith not familiar with high speed revolver operation will weaken the cylinder stop spring. This will often enlarge the upper half of the stop notch on the cylinder. Damage can be so severe as to warrant cylinder replacement. Smith makes the 625 cylinders on the soft side to prevent fragmentation in the event of a catastrophic failure. The softer metal peels rather than shatters. Jerry M and I talked about induction hardening the cylinder stop notches to prevent peening. If one was worried about peening, a simple solution is to hard chrome the cylinder. The harder surface reduces the peening. Jason Pettitt's 627 shows little deformation and he's shot a lot of rounds thru it.

Randy

[spook]

Very interesting Randy. I always thought that Hard Chrome would just keep sliding surfaces form wearing. I figured that direct impact like a cylinder stop and a cylinder notch wouldn't stop the wear/peening with surface treatments like Hard Chrome, because the thin layer of Chrome wouldn't be enough to stop deformation of the softer underlying material.....

I just read this back and I hope it makes sense

[Randy Lee]

Hi Spook,

The harder surface seems to at least slow the effects of impact. I noticed on the 38 supers with the Melanite hardened finish, that peening is minimal as well.

Randy

[spook]

Cool! I am looking for a way to keep my new revolver "new". I might try something like this (though I'll probably go with Titanium Nitride). Thanks for the info!

[Patrick Sweeney]

Replace that stretched cylinder stop spring with a new one, pronto. Stretching springs is only a temporary solution at best. When you can, turn it over to a good wheelgun 'smith to have the timing looked at. Proper timing can do a lot to reduce peening, and preclude "throwby" where the hand slings the cylinder past the cylinder stop.