FTF model 66-8 2.75”

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K13

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New 66-8 S&W 357 has been having several FTF. I recently purchased 1000 rounds of Armscor 124gr 357 and had a FTF almost every cylinder. The worst being only 2/6 firing. Single action had better results. Haven’t tried any other ammo yet. Has anyone had a similar issue? Resolution?
 
It was about 2.5 turns loose. I tightened it up after applying blue loctite. While shooting it the cylinder release and rear sight screw backed out. Maybe that was the issue. Everything is loctited in now. Will see if it’s fixed.
 
I recall also having some trouble firing Armscor .38 Special ammo.
Besides your strain screw backing out, I suspect Armscor's primer are either hard or not completely seated. The rounds typically fired on a 2nd hit.
 
"Single action had better results."

That doesn't seem right because DA pulls the hammer further back (with more spring pressure) than SA.
 
Actually the hammer/ firing pin hits harder in single action on all the S&W revolvers I own. Light strikes are more common in DA. A backed out strain screw would definitely cause the issue.
 
2.5 turns loose is pretty loose. There's a decent chance that correcting the loose screw issue will fix your problem.
 
Carmady said:
"Single action had better results."

That doesn't seem right because DA pulls the hammer further back (with more spring pressure) than SA.
Click to expand...

Nope. You have it backwards. The hammer on S&Ws goes back farther on single action than it does on double action.
 
"Nope. You have it backwards. The hammer on S&Ws goes back farther on single action than it does on double action."

You're right, thanks.
 
The strain screw on S&Ws should not be "tight". They come from the factory with the screw head flush with the frame, and that's where it belongs.

Various "experts" will tell you how to "adjust" mainspring tension (and trigger pull) using the strain screw, and it will do that, but that isn't what its for.

It's there as an aid to disassemble the gun.

Because its a screw, that will turn in and out, some people just can't keep their hands off of it. And, of course their adjustments are an "improvement", until they get to the point of having misfires...at which point some will blame S&W for having "weak" mainsprings....:rolleyes:
 
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