S&W Revolver Problems

[Tatume]

Recently I acquired a Model 25-2 from the early 1960s, the action of which has been tuned. I know this because the trigger has an over-travel stud threaded into the back of the finger lever. The gun has two problems.

1. The hammer block is missing. The side plate is milled for the hammer block, and the rebound slide has the pin. If someone could help me locate a correct hammer block, I would be grateful.

2. Apparently the double action dog has been shortened. If I draw the hammer back in double action mode, but stop before releasing the hammer, and then slowly release the trigger, the hammer drops. This occurs just before the hammer comes to rest; there is insufficient force to fire a cartridge. Nevertheless, I may need to replace the dog. I'd like to hear opinions on this.

Thanks, Tom

[garandsrus]

It sounds like the gun was set up for Double Action shooting games such as PPC. Many hammers are bobbed so single action isn’t even possible. The trigger stop lets you know where the trigger will break when a little more pressure is applied. Some people took out the hammer block on target pistols so the pistol had a smoother trigger pull. It works fine but is no longer safe to carry with 6 shells.

[Outpost75]

I would return it to S&W for repair. No telling what else Bubba did to it. Gun is unsafe to shoot as it is now.

Hope you got it real cheap, otherwise an expensive lesson. Any chance of returning it and getting your money back?

[DCB]

Check gun parts they might have what you need
https://www.gunpartscorp.com/gun-manufacturer/smith-wesson/revolvers-sw/25-2

[DCM]

I would start with backing out the screw that puts tension against the hammer spring a bit. Many folks often screwed this in to make a lighter trigger pull, but one needs to use sensitive primers to make this whole system work then. the screw is located under the grips. There does need to be some tension on it but not a ton.

[pietro]

.

Any N-frame (Models 24, 25, 27, 28, 29, 57, 58, 624, 625, 627, 629 657) action parts would fit your gun.

The slide & fly are AFAIK straight replacement parts that don't need specific fitting, unless bubba has gone above & beyond.

.

[skrapyard628]

I would start with backing out the screw that puts tension against the hammer spring a bit.

Bad idea.

The common bubba fix for lightening the trigger pull is to unscrew the strain screw on the mainspring. Its not a great idea and can cause the screw to loosen up even more over time causing light strikes. Some people would use locktite on it after unscrewing it...still a bad idea but better than no locktite.
Another bubba fix is to shorten the screw so that it can still be tightened down all the way.

None of those are really a "great" way to lighten the tension on the mainspring. But the best would be to shorten the screw and use locktite.

If the strain screw looks questionable just order a new one and screw it in all the way if youre looking for absolute reliability.

[Drm50]

The strain screw is not intended to be an adjustment. The main spring is designed to load with screw seated. I have seen guys shimm Spring, stone spring and other tricks. Usually ends up with broke spring. Gun is not safe without hammer block.

[Tatume]

Good news! The gun is now repaired, $12. Thank you.

[Green Frog]

So give... what did you have to do? I assume you did it yourself since most gunsmiths would charge you more han $12 just to look at it.

your Friendly Frog

[Tatume]

So give... what did you have to do? I assume you did it yourself since most gunsmiths would charge you more han $12 just to look at it.

The gunsmith is a friend of mine. He had parts on hand. The hammer block is a drop in. We tried a DA dog; it worked beautifully without fitting. Done, $12 for parts.

[DCM]

Bad idea.

The common bubba fix for lightening the trigger pull is to unscrew the strain screw on the mainspring. Its not a great idea and can cause the screw to loosen up even more over time causing light strikes. Some people would use locktite on it after unscrewing it...still a bad idea but better than no locktite.
Another bubba fix is to shorten the screw so that it can still be tightened down all the way.

None of those are really a "great" way to lighten the tension on the mainspring. But the best would be to shorten the screw and use locktite.

If the strain screw looks questionable just order a new one and screw it in all the way if youre looking for absolute reliability.

NO the bubba fix Was to screw in in the screw making less tension for the spring for the hammer.
I had this done to mine by someone that claimed to know what they were doing. When I asked why I was getting light strikes he returned it to the factory setting. It worked fine after that but the trigger pull wasn't nearly as nice.
This screw needs to be properly tensioned as I said before.

[garandsrus]

Screwing it in increases the tension on the hammer spring. To remove pressure on the spring, you unscrew the strain spring screw.

I have heard of people putting a spent primer case on the end of the screw so you could add extra tension by basically lengthening the screw. I have never had a reason to try it.

[DCM]

Here is a link to a book by a noted authority.
https://www.amazon.com/Revolver-Shop-Manual-Covers-Actions/dp/B000MRFUWY

In = righty tighty = clockwise from the slotted, hex, phillips etc end of the screw. This will put more tension between the screw and spring, reducing the trigger pull. This will also reduce the force with which the firing pin hits the primer.

Semantics??

[garandsrus]

Well, if there is no tension on the screw/spring, there is nothing to push the hammer forward. Tension is removed by turning the screw out. If the screw is fully seated, turned in, there is as much tension as you can get.

One of your quotes is "You won't know until you Actually try it", so even though I was sure, I tried it. I picked up one of my Smiths and turned the screw in and out and checked the trigger pull in Double Action. Simply feel, no trigger scale. As the screw was turned in, the trigger pull increased. Turning it out decreased the trigger pull. Turn it out far enough and the hammer won’t even drop. The difference was very noticeable. I left the screw about 1/2 turn farther out than when I started, so the trigger pull is less than it was. I will need to see if it still reliably ignites primers since the hammer will also have less force. I had no issues with ignition before.

I also checked two S&W’s that have been converted to PPC guns, a Model 10 and 686. Both have bobbed hammers and are intended to shoot double action only. Both have very light trigger pulls that require the use of Federal primers for consistent ignition. If I partially pull the trigger to start the hammer back and then pull the hammer back with my fingers, neither one will lock the hammer back. Both of the pistols have rubber trigger stops. That’s why I suggested that the gun in the OP had been converted to shoot double action only.

[JonB_in_Glencoe]

Are you saying more tension on the main spring will lighten the DA trigger pull ?

[brassrat]

258867

[Petrol & Powder]

So, for the record and not trying to anger anyone - The strain screw on a S&W K/L/N revolver is NOT an adjustment screw for the mainspring.
That screw should not be shortened OR backed off to reduce the tension on the mainspring. That screw should be fully tightened so that the head bottoms out in the recess.
It is a common Bubba gunsmithing fallacy that the strain screw is somehow meant to be some type of adjustment screw - IT IS NOT AN ADJUSTMENT SCREW.

[Tatume]

So, for the record and not trying to anger anyone - The strain screw on a S&W K/L/N revolver is NOT an adjustment screw for the mainspring.
That screw should not be shortened OR backed off to reduce the tension on the mainspring. That screw should be fully tightened so that the head bottoms out in the recess.
It is a common Bubba gunsmithing fallacy that the strain screw is somehow meant to be some type of adjustment screw - IT IS NOT AN ADJUSTMENT SCREW.

Beg to differ. Please refer to "The S&W Revolvers, A Shop Manual" by Jerry Kuhnhausen, 5e, pg 81, Bench Note 3: "The mainspring strain screw must be fully threaded in and seated in the frame. Mainspring arching, tension and weight are reduced by trail adjusting strain screw extension length and not by loosening the strain screw."

[Petrol & Powder]

I'm not going to dispute what Mr. Kuhnhausen wrote but I will say that I've seen a bunch of S&W strain screws shortened but I've never seen one that needed to be shortened.

And we are in agreement that the strain screw should always be fully tightened so that the head is seated and not loosened to adjust the tension on the mainspring.

[Outpost75]

Beg to differ. Please refer to "The S&W Revolvers, A Shop Manual" by Jerry Kuhnhausen, 5e, pg 81, Bench Note 3: "The mainspring strain screw must be fully threaded in and seated in the frame. Mainspring arching, tension and weight are reduced by trail adjusting strain screw extension length and not by loosening the strain screw."

NEVER! DO THIS ON A GUN YOU WILL CARRY!

Was sometimes done for a paper puncher, but testing by the ammunition companies and also at BRL has proven that striker energy of less than 0.010" copper indent as measured using the "C " size copper in the government gage holder in .38 Special increases velocity variation and induces significant and readily noticable increases in vertical dispersion at 50 yards.

[Tatume]

There is no better source of reliable information on S&W revolvers than Jerry Kuhnhausen. He gives factory specifications, and demonstrates how to achieve factory specs. Kuhnhausen is a much better source of information than Internet "experts."

[Outpost75]

There is no better source of reliable information on S&W revolvers than Jerry Kuhnhausen. He gives factory specifications, and demonstrates how to achieve factory specs. Kuhnhausen is a much better source of information than Internet "experts."

Factory-trained law enforcement armorers and the government's weapon engineers at FLETC, NASC Crane, IN, FBI Quantico, Picatinny Arsenal and BRL would disagree.

[StrawHat]

When I attended the S&W Armorers School, we were taught to screw the strain screw in tight and leave it alone.

Pretty sure the instructor knew his way around the S&W revolver. That screw is not for adjusting the tension on the mainspring.

Kevin

[Outpost75]

I attended S&W police armorer's school in 1982 and was taught by Chet Grondalski and Archie Duibea (sp?) I could tell stories out of school of contract goings on which were investigated by Feds. Suffice to say in that era corporate morality was on a par with VW emission testing today....

[curioushooter]

I've found ebay to be a great resource. Try looking for N frame parts...you may even find one out of a 25 of the same vintage. Though I hate it when people mess with the hammer or anything connected to it!!!

Strain screws are available. Besides...every S&W seems to benefit from a Wolffe type I or type II. Wolffe will throw in an extra long one if you ask.

Get Kuhnhausen's book.

If push comes to shove you can sell it.

All S&Ws with external hammers should have the hammer block. Sheesh. My 442 doesn't have one since the hammer is internal. I cannot tell vs. my wife's 638. Why people remove them is beyond me.