[rjk2475]

is it ever advisable or safe to to use this screw to minimally lower da trigger pull?

[M58]

Generally no.
As it will work its way out more.
In the days before Wolffe Springs and such, we would file the screw down just a bit and tighten it up again. If you took too much off it meant a new screw or one solution was a fired primer over the screw to add metal.
So generally no.
Spring kits are now available for just about all.

[Standing Wolf]

I always reduce the tension on a Smith & Wesson revolver's main spring to the point at which it reliably detonates primers, then tighten it a quarter to a third of a turn just to be extra-sure.

[ruger357]

I was told by S&W not to adjust it.

[JimC]

I was told by S&W not to adjust it.

Exactly what I've heard them say more than once.

While attending an Armorer's course at S&W many years back, one of the instructors said, "we wish we had never put that screw on the guns, you guys just can't leave things alone". :banghead:

Before I attended the school, I used to back it out some but haven't done so since the S&W comments. ;)

[Kahr carrier]

Nope I wouldnt loosen it.:)

[bountyhunter]

YES, you can use it to adjust main spring tension. I would never do it on a defense or service revolver, but I do it on my comp guns.

"I always reduce the tension on a Smith & Wesson revolver's main spring to the point at which it reliably detonates primers, then tighten it a quarter to a third of a turn just to be extra-sure."

I agree with this post but would add: be sure to use some blue Loc-tite on the threads so it can't wander out and start light striking during a match (imagine how I know that). BTW: most SW wheelguns with STOCK springs and strain screws can handle about 3/4 of a turn out on the strain screw and still fire most ammo reliably.

[J Miller]

JimC,

I keep mine tight, but..............
Back in the late 70's early 80's when I was doing a lot of revolver shooting the "in" thing was to bevel the edge of the strain screw and then screw it in thight. Something about the sharp edge of the strain screw suposedly causing a fatigue strain on the main spring at the point of contact.
Both my N frames are done this way. I have been considering replacing the screws with unaltered ones.

What say you?

[Mike Irwin]

"Something about the sharp edge of the strain screw suposedly causing a fatigue strain on the main spring at the point of contact."

I'm pretty certain that's what caused the mainspring on my one S&W revolver to snap. It snapped right at the line where the top edge of the screw would contact the spring.

Of course, it took 82 years for that to happen to the mainspring on my .32 S&W Long Regulation Police, made in 1917... :)

[JimC]

J Miller,

Back in the '70's when I was shooting PPC competition, the "thing to do" was to round off and highly polish the contact point of the strain screw and screw in in all the way.

I had a couple of competition S&W's that the screw was done in this manner. It actually shortened the screw some. But, these guns were only used for competition, not duty or carry in any manner.

Before any match you would test your gun with your match ammo to be sure it would be 100%.

By backing the screw out and relieving tension on the main spring, you will actually cause the main spring to take a set after a long period of time.

I recall one idiot LEO that carried a S&W M15 on duty, finding out while he was cleaning that gun that he had "lightened" the trigger pull in DA by backing out the screw.

He carried that M15 in that condition until the next qualifications where, he had a constant 4 out of 6 rounds misfire with factory service ammo.

When we looked at the gun to determine why he was having the misfires, he told us what he had done! :eek:

"Something about the sharp edge of the strain screw suposedly causing a fatigue strain on the main spring at the point of contact."

I have a couple of S&W's lying around for a long time that the strain screw has always been socked up tight and have never had a problem.

[mec]

Ron Power used to put a ball detent in the strain screw and number it around the edges for repeatability. this was for ppc guns and is ok if you know your primers, but sometimes hammer-fall is marginal right out of the box.

I always check smiths with cci primers to see if they are good to go double action.

82 years. One gunsmith told me the Smith mainsprings would last forever and I suspect 82 years comes pretty close to that.

[J Miller]

JimC,

OK, here is a question. Are all the strain screws the same?
I'm not haveing problems with misfires, but I think I'll get some spare screws just because.
I have a late 50's mdl 28, and a 81 vintage 25-5.

J

[JimC]

OK, here is a question. Are all the strain screws the same?

You got me on that one. I haven't played around with a revolver in this manner for years.

I'm going to stick my neck out here and say from memory, for the older carbon steel guns [blued] they are.

For the new ones, I haven't a clue nor do I have a current parts list for S&Ws. :(
Hell, I need to look at pictures to figure out what model numbers are which any more. :)

[Mike Irwin]

The ones that I've examined on K, L, and N frames, yes, they appear to be the same length and diameter.

I don't know about the I-frames, I so rarely take my Regulation Police apart.

J-frames don't use a strain screw.

[bountyhunter]

The screws have different part numbers from Brownells so I think maybe they are different.

[Zander]

With a nod to all those who advise reading Kunhausen's seminal work of S&W 'smithing, let me suggest that you buy a replacement mainspring, the PowerRib, from Wolff's.

Do polish the screw tip...and do add a little a grease [I like Tetra Gun gun grease] to the screwtip so that friction will be at an absolute minimum.

You'll be surprised at the improvement...

[Mike Irwin]

I just realized that my reply is BADLY worded, and appears to give an answer 100% different than what I wanted.

What it SHOULD say is that I've compared the screws from K frames against each other, N frames against screws from other N frames, etc.

Not a K frame screw against one from an N frame.

Although I should do that.