DA Revolvers, Trigger Weight, and Safety Lever

There are several ways to lighten the hammer spring, including the incorrect method of backing out the strain screw. The correct way to lighten the hammer spring is to replace it with an aftermarket spring.

I am sure it is not the right way to do it. Just wondering what adverse consequences backing out the screw would cause. Will it break anything, or cause stacking?

The Rebound Slide Spring is also compressed when the trigger is pulled. The trigger strut physically pushes the Rebound Slide backwards, you can see it in the second photo. The Rebound Slide has nothing to do with firing a cartridge, it is what pushes the trigger back forward again when you let go of the trigger.

Rebound spring does more than resetting the trigger, at least so in newer designs. It also rebounds the hammer so that the safety bar can slip between the hammer and the frame. It is important not to have the firing pin resting on the primer, or it may go off when it is dropped.

Is a Safety device needed on any of these guns? Absolutely not. No way they are going to discharge unless somebody pulls the trigger on purpose.

Most modern revolvers have the safety bar. It is a form of internal safety. The safety device is already there, built in.

-TL
 
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Backing out the main [hammer] spring tension screw lightens the fall of the hammer quite possibly resulting in failure to fires. Although it does lighten the trigger pull…. at what cost?????

Not a good idea at all for a duty/carry/self defense weapon.

A good smith can polish bearing surfaces to the point that, even with full pressure on the main spring the pull is so smooth and even it feels much lighter. Good for accuracy good for reliability.

Some competition guns, like my Davis PPC model 10 mentioned above, replaced the factory leaf spring with a coil spring mechanism. This definitely lightened the trigger pull. however the hammer on this gun is also bobbed [lighter] and no SA sear notch…DA only. I had the gun built in the mid 70's and over the years it must have well over 100,000 rounds through it easily. Never had a FTF that I can remember and still going strong.

Mike
 
I am sure it is not the right way to do it. Just wondering what adverse consequences backing out the screw would cause. Will it break anything, or cause stacking?

Howdy Again

The problem with loosening the strain screw to adjust hammer spring strength is that if you loosen it too much, when you cock the hammer the spring will interfere with the frame. The hammer will suddenly get very stiff. Trust me on this. And without the screw being locked down, it can back out.

Rebound spring does more than resetting the trigger, at least so in newer designs. It also rebounds the hammer so that the safety bar can slip between the hammer and the frame.

Yes, I am quite aware that the Rebound Slide also wedges the hammer back, I just didn't want to make my answer too complicated. Rebound Slides have been doing that since 1905. If you look carefully at my photos you can see the hump on the top of the Rebound Slide forcing the hammer back slightly.

The proper name for the 'safety bar' is the Hammer Block. It is in position in one photo, I removed it for clarity in the other photo. That is the Hammer Block that was first incorporated during World War Two after an unfortunate incident on a warship.

Previous to that time, there was a Hammer Block mounted on the side plate. It was activated by a ramp on the pawl. Here is a photo of an M&P that shipped in June of 1939 with the old style Hammer Block. The piece itself is a piece of spring steel peened into a slot in the side plate. You can see the ramp on the pawl. This style of hammer block was normally in position blocking the hammer. When the pawl rose, it pushed the spring loaded Hammer Block out of the way.

MPRoundButtandSidePlate.jpg



The earliest Hand Ejectors had no Hammer Block at all. They simply depended on the Rebound Slide to wedge the hammer and firing pin back away from the primer of a round under the hammer.

It is important not to have the firing pin resting on the primer, or it may go off when it is dropped.

That sir, is completely untrue with a modern S&W revolver. That is why the modern (WWII Era) Hammer block was developed. There are actually two, redundant safety devices built into a modern S&W. First, there is the Rebound Slide, Which ever since 1905 has pushed the hammer back so that the firing pin does not rest on a primer. Not content to rely just on the Rebound Slide, at some point S&W incorporated the earlier type of Hammer Block pictured in this post. The shipboard incident occurred after a Victoy Model was dropped from the superstructure of a warship and fell to the deck where it landed on its hammer. Investigation indicated that the spring loaded Hammer Block in the gun probably failed to function because it was probably bound up with Cosmoline. The Government told S&W that if they wanted to keep their wartime contracts, they better come up with a fix, which they did over the course of one week. Ever since that time, ALL S&W revolvers have incorporated the sliding Hammer Block. You can drop one onto its hammer from as high as you want, it ain't going to fire.
 
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Not on a double action revolver but on a single action frankengun that I bought a handful of years back for my sons to shoot 22s. It is one of those Heritage Rough Actions... er... Rough Riders! It has a ridiculous lever to the left of the hammer near the top of the frame that cams the hammer back from rest a good 1/8th of an inch. Mind you the pistol has no transfer bar, so in light of that it actually does serve a purpose in the respect of someone holstering it for carry with all six chambers filled. The other purpose it served was allowing me to dry fire a rim fire pistol in order to help smooth out the action which now is actually smooth and pleasant. That ugly little bugger is actually a tack driver too. Well worth the $150 that I paid for it. Here are a couple of pics with it on and with it off to show what I mean.
Sorry, not meaning to hijack the thread.

IMG_20150223_190942593.jpg

IMG_20150223_192101613.jpg
 
AH!
Never handled one of the Heritages, did not know they had an actual safety "lever".
Thanks! :)
Denis
 
The problem with loosening the strain screw to adjust hammer spring strength is that if you loosen it too much, when you cock the hammer the spring will interfere with the frame. The hammer will suddenly get very stiff. Trust me on this. And without the screw being locked down, it can back out.

So I guess it would be OK if one doesn't back out the screw to much. I am doing a fraction of a turn myself. I wouldn't worry the spring backing out from its saddle. It is being trapped between the grips.

That sir, is completely untrue with a modern S&W revolver. That is why the modern (WWII Era) Hammer block was developed. There are actually two, redundant safety devices built into a modern S&W. First, there is the Rebound Slide, Which ever since 1905 has pushed the hammer back so that the firing pin does not rest on a primer. Not content to rely just on the Rebound Slide, at some point S&W incorporated the earlier type of Hammer Block pictured in this post. The shipboard incident occurred after a Victoy Model was dropped from the superstructure of a warship and fell to the deck where it landed on its hammer. Investigation indicated that the spring loaded Hammer Block in the gun probably failed to function because it was probably bound up with Cosmoline. The Government told S&W that if they wanted to keep their wartime contracts, they better come up with a fix, which they did over the course of one week. Ever since that time, ALL S&W revolvers have incorporated the sliding Hammer Block. You can drop one onto its hammer from as high as you want, it ain't going to fire.

That's my point exactly. The safe bar, hammer block rather, serve this purpose. But it requires the rebound slide to rebound the hammer a little. Hence, the rebound spring is not only to reset the trigger.

-TL
 
Seems to me if a person can't learn to shoot a stock SW revolver with factory designed settings perhaps DA revolvers aren't for you.

I'm 66 and I just did a department qualification with a 2" model 10 on Saturday. Full spring tension 8+ pound trigger pull. It's not that hard.

I certainly wouldn't go screwing around with a gun I was going to bet my life or my partner's life on.

If you're not comfortable shooting it like it was designed to be shot……

Get a Glock.

Mike
 
Driftwood Johnson said:
...And without the screw being locked down, it can back out.
tangolima said:
So I guess it would be OK if one doesn't back out the screw to much.
There aren't really degrees of locked down. Backing out the screw at all means it's not locked down.
I wouldn't worry the spring backing out from its saddle. It is being trapped between the grips.
The issue isn't with the spring backing out, it's with the screw backing out.
 
There aren't really degrees of locked down. Backing out the screw at all means it's not locked down.The issue isn't with the spring backing out, it's with the screw backing out.
I see. The screw could back out with use, although it is under heavy load from the spring tension. I guess loctite or staking may help double ensure. Certainly not the best way to lighten the spring. I'm just curious about its technical implications. I do that on my model 10 that is not for self defense. Thanks.

-TL
 
Discounting the Webley, I couldn't imagine a place on a revolver to stick a safety lever, till the Heritage was pointed out. :)

Still not practical on a DA, though.
Denis
 
Now you mention it, I guess the ram levers on my percussions ARE safety levers.

If I swing 'em down far enough for the ram to stick inside the chamber, the cylinder can't rotate & the hammer can't be cocked to fire.

Brilliant!
Why did I never realize that before?????
Denis
 
Just for fun, let me throw this in:

A few years ago a shooter asked me to fire his pistol, a .45 Colt/.410 over/under pistol. The gun looked robust enough and well made, so I though "Why not?"

The pistol had a spring loaded cross pin type safety, that worked with the hamer being at full cock. Pushing the pin in until it clicked locked the safety pin in place, a second push freed it to pop out for firing.

I loaded two rounds into the chambers and raised the gun to fire. All I got was a click of the falling hammer. I gripped this pistol as I did my sixshooters, thumb of my shooting hand held high alonside the frame.

What had happened is that my high thumb hold had depressed the safety and blocked the hammer fall. In a dangerous situation, could have been bad medicine.

Just food for thought.

Bob Wright
 
I see. The screw could back out with use, although it is under heavy load from the spring tension. I guess loctite or staking may help double ensure. Certainly not the best way to lighten the spring. I'm just curious about its technical implications. I do that on my model 10 that is not for self defense. Thanks.

You are missing the point. The strain screw is not meant to be a spring adjustment device in a S&W revolver. The reason the strain screw is there is to allow the spring to be installed or removed from the gun. The hammer spring can only be installed in its slot at the base of the frame in the straight, unbent condition. Once the spring is in place, the strain screw is tightened against the spring to bring it to the proper tension.

The fact that backing the screw out slightly will lighten hammer force is not part of the design intent. Yes, many shooters back the screw out a half turn or so to lighten the trigger pull, I have done so myself. But the proper way to do it is to either install a lighter, after market spring, or grind down the spring to lighten it. One could also shorten the strain screw so that it does not bear down as hard against the spring when fully snugged. A fully snugged screw will always hold its position better than one that is not fully seated. That is part of the nature of screws and the interference generated in the threads when the screw is firmly snugged.
 
You are missing the point. The strain screw is not meant to be a spring adjustment device in a S&W revolver. The reason the strain screw is there is to allow the spring to be installed or removed from the gun. The hammer spring can only be installed in its slot at the base of the frame in the straight, unbent condition. Once the spring is in place, the strain screw is tightened against the spring to bring it to the proper tension.

The fact that backing the screw out slightly will lighten hammer force is not part of the design intent. Yes, many shooters back the screw out a half turn or so to lighten the trigger pull, I have done so myself. But the proper way to do it is to either install a lighter, after market spring, or grind down the spring to lighten it. One could also shorten the strain screw so that it does not bear down as hard against the spring when fully snugged. A fully snugged screw will always hold its position better than one that is not fully seated. That is part of the nature of screws and the interference generated in the threads when the screw is firmly snugged.
I understand the screw is not meant to be a means for main spring tension adjustment; just like the main spring is probably not meant to be ground down. What I am interested is the adverse effects it may bring if I back it out a fraction of a turn. The screw may continue to back out causing the revolver inoperable, that I get. Other than that there is nothing, yet. Thanks.

Edit: I can add a piece of thin metal behind the spring saddle and then cinch down the screw. Same effect and the screw won't back out.

-TL
 
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tangolima said:
What I am interested is the adverse effects it may bring if I back it out a fraction of a turn. The screw may continue to back out causing the revolver inoperable, that I get. Other than that there is nothing, yet.

No permanent damage, but "clicks" when you really need "bang" is about as adverse an effect as you can get, so anything else is moot, seems to me.
 
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