Model 25-2 off-primer strikes in SA mode

[Ohio Smitty]

I now own a S&W Model 25-2 in .45 Colt with the hammer nose firing pin. Both SA and DA operation feel smooth and normal. Primer strikes in DA operation are nicely centered and appear to be of normal depth. SA strikes are sufficiently off-center the revolver generally fails to fire SA, and some are so far off as to hit the cartridge head.
I described the problem by email to S&W customer service. It diagnosed the cause as a loosened strain screw. The screw appeared tight on my exam, but I backed it out, added lock-tite, and cranked it in as far as it would go.
To the range, but still no joy in SA function. I would appreciate your expert advice on diagnosis/repair.

 

[jaybar]

Bolt stop problem???

First off - 25-2 is chambered in 45 ACP not 45 Colt. You didn't specify where off-center the strikes were. If they are toward 3 o'clock then the cylinder is over- rotating which means that the bolt stop is not catching in the cylinder notches. The faster you cocked the hammer for single action firing the more off-center the hits would be.Check the bolt stop for binding in the frame or a weak or broken spring. If the off-centers are toward 9 o'clock then you have a timing problem with the hand not rotating the cylinder far enough. I doubt this is the case since you would normally see this in DA firing and not SA since the hand travel is shorter for DA then it is in SA mode.

 

[Jim K]

That "answer" blows me away! I can't see how the strain screw or mainspring tension could have anything to do with what you are describing.

As jaybar says, can you describe where the firing pin is hitting? It sounds as if in DA fire, the cylinder is rotating to the right point on momentum, but if you cock the gun slowly in SA the cylinder won't rotate all the way.

With the gun empty, can you try cocking the gun rapidly in SA and see what happens? If it locks up properly that way, the problem would seem to narrow down to the hand or the ratchet (on the back of the cylinder).

You say you "now own" the gun, which seems to imply that you bought it used. If so, and if you bought it from a store, try to get them to fix it or return it to S&W. If they can't/won't, and you can't get someone local to fix it, I recommend returning it to S&W, though hopefully not to the person who thinks the problem is the strain screw.

Jim