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12-15-2016, 11:23 PM
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Re-curving main springs?
Anyone do this? I tried it for the first time because the trigger in my 22-4 was about 75 pounds from the factory. I installed an 11# rebound spring and have attempted to relieve some mainspring tension until the trigger can reset with the 11# rebound spring and a polished rebound slide. Results are pretty good so far. Groups sizes are down, and there's more skin left on my trigger finger.
Is there a downside to attempting to re-curve the factory main spring? I've never done this before, and just figured why the heck not try it. Main springs are cheap enough if it breaks.
Last edited by SLT223; 12-15-2016 at 11:25 PM.
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12-15-2016, 11:33 PM
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Probably easier on both you and the mainspring to just remove some material from the mainspring strain screw instead.
Also, an 11 pound rebound spring is pretty light to expect to just "drop in".........
you might check your single action trigger pull also....and for push off.
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Last edited by armorer951; 12-15-2016 at 11:34 PM.
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12-16-2016, 10:00 AM
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Quote:
Originally Posted by armorer951
Probably easier on both you and the mainspring to just remove some material from the mainspring strain screw instead.
Also, an 11 pound rebound spring is pretty light to expect to just "drop in".........
you might check your single action trigger pull also....and for push off.
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Agreed on all fronts! I'm out of strain screws, but have one more S&W main spring. No push off, so good there. My main concerned is if changing the shape of the main spring predisposes it to breaking. If yes, then I don't want to leave the gun set up the way it is. I can re-do it when I get more strain screws.
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12-16-2016, 11:10 AM
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You can lower the trigger pull quite a bit by putting a large radius bend in the middle. Avoid any sharp bends, especially near the top. You will need a longer strain screw if you do this. I use a #8-32 x 1/2" socket set screw and blue LocTite for this. That allows you to tune the spring to get the minimum amount of spring force that gives reliable ignition.
Warning!!! Do NOT do this on any carry or duty gun! This is only for target shooting and competition guns. Carry and duty guns must remain in stock configuration to make sure they are reliable in an emergency!
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12-17-2016, 02:48 PM
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I have recurved lots of the S&W mainsprings, never had one break. I recurve the upper one third of the spring, a nice gradual curve, no sharp bents. A little bent at a time, with the goal to have the revolver fire in D/A reliably, with about a 3/4 of a turn left on the strain screw for good measure. Use blue locktite on the screw.
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12-31-2016, 03:28 PM
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Where are you getting strain screws for a square butt k frame?
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12-31-2016, 04:28 PM
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Have you tried S&W Customer Service/Parts? (sq. butt strain screws)
1-800-331-0852
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01-05-2017, 01:01 PM
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Quote:
Originally Posted by SLT223
Anyone do this? I tried it for the first time because the trigger in my 22-4 was about 75 pounds from the factory. I installed an 11# rebound spring and have attempted to relieve some mainspring tension until the trigger can reset with the 11# rebound spring and a polished rebound slide. Results are pretty good so far. Groups sizes are down, and there's more skin left on my trigger finger.
Is there a downside to attempting to re-curve the factory main spring? I've never done this before, and just figured why the heck not try it. Main springs are cheap enough if it breaks.
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Afternoon SLT223
If you did a gradual re-curve from center & up then you won't have any issues with it.
I almost always re-curve the main spring rather than clip the strain screw as changing the strain screw length also changes the spring-to-hammer working angle (usually not a positive or desired change).
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01-05-2017, 01:07 PM
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All you have to do is take some width off each side of the lower half of the mainspring, where the meat of the spring is. Do it in increments. Don't mess with the curvature of it.
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Last edited by bluetopper; 01-05-2017 at 01:10 PM.
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01-05-2017, 01:41 PM
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I agree totally with "bluetopper". IMHO, after a spring is created and sized for a particular job it is inviting failure at an inopportune time to re-bend that spring. But, on leaf springs reducing the cross section of the leaf by grinding off equal amounts from each side is acceptable. Caution must be taken to not over heat the leaf spring thereby re-tempering it to some other than original tensile strength. BUT, in reality, I think the best option is to purchase a set of mainsprings from Wolfe and work with them. .....
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01-05-2017, 03:07 PM
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Springs are cheap. If you have the skills and desire to tinker, then go for it. The worse you will do is ruin a spring. Springs like this can be altered, but it needs to be done properly. The question of why comes up when there are aftermarket reduced power springs readily available, or you can achieve the results another way.
I had a case just like yours with my 629. It had a DA pull of at least 15#. I installed an 11# rebound spring, then adjusted the strain screw until the trigger would reset. Also did all the internal polishing. It now has a crisp 2# 5oz SA trigger and a smooth 9# DA trigger.
Some things to be aware of:
You will most likely need to do something to lower tension on the mainspring if using an 11# rebound spring because the trigger will not reset usually. Strain screws can be had relatively cheap too, so I just modified that. It does change the geometry of the spring, but you can do it safely to a certain extent which is usually enough to get the results wanted.
Due to modifying the mainspring position, if you go the strain screw adjusting route, you will have to watch how the grips fit. After modifying the strain screw to relieve tension on the mainspring, I found out that the factory Pach grips will no longer fit because the grip screw is blocked by the mainspring since the position has changed. However, I have Ahrend combat grips on it that work fine due to the grip screw location being different. So it worked out for me.
The less spring pressure the more opportunity for hammer push off due to the S&W cocking notch design. So you will have to make sure your trigger sear is perfect and the cocking notch is perfect too. Trigger sear can be cleaned up if necessary, but takes skill.
As with any revolver smithing, if you don't have confidence, then don't do it. It takes a lot of skill and patience working on revolvers. Not everyone can do it. Alter or modify the cheapest and easiest parts to replace first.
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01-05-2017, 05:17 PM
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I have found that springs that are properly heat treated can be re formed and will hold the new shape. I make mine an S curve and have reliable 5.5 - 6 lb. DA. I never shoot SA. No need with a good DA. There are some other things involved in getting the action to work well at this poundage, it's not just springs.
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01-05-2017, 06:28 PM
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Toolguy offers some great advice. Very few people understand what it takes for a double action trigger pull on a competition revolver... Waren does.
Tom
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01-05-2017, 06:44 PM
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Thanks for the kind words Tom!
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