I think the S&W 640 is the perfect pocket pistol, even if it is a bit heavy. But this DAO revolver has quite a stiff trigger pull and I am thinking about having the springs changed to ones that would give an easier and smoother feel. Will I be taking any risk that will affect the reliability of the gun or that the chamber will not rotate properly? I've never tampered with the springs of any of my revolvers before this but the heavy trigger pull I'm afraid would make my accuracy in a SD situation even worse than it otherwise might be.
Changing springs in my S&W 640
- Thread starter vito
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Check out these guys. The video will help in your decision.
http://www.apextactical.com/
http://www.youtube.com/watch?v=JIUfmg1JulE
http://www.apextactical.com/
http://www.youtube.com/watch?v=JIUfmg1JulE
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Lighter springs will reduce the felt pull weight, but they won't make the action smoother. Some people have good results with reliability with lighter springs, though if I were you I would have to do a LOT of testing to trust a spring configuration that is softer than factory. I personally would not mess with it.
Is it a new 640? When I first got my 642 (NIB), the trigger was stiff and gritty. After 1,000 or so trigger pulls, I cleaned out and re-oiled the internals. It is now as smooth as my other S&Ws, though the pull is still a little heavier. But I'm fine with that. Low pull weight isn't the be all, end all. My Springfield 1911 Mil-Spec had a terribly rough trigger with a jerky release. The pull weight was probably around 5 lbs, but I couldn't achieve better than a 6" group at 7 yards with a junky trigger like that. OTH, I can achieve one hole groups at the same distance with a smooth DA trigger at 10 lbs or more. It just takes some getting used to.
With the lower mass of a J Frame's hammer, stiff springs are a tradeoff to insure reliability to ignite all factory primers/loads.
Is it a new 640? When I first got my 642 (NIB), the trigger was stiff and gritty. After 1,000 or so trigger pulls, I cleaned out and re-oiled the internals. It is now as smooth as my other S&Ws, though the pull is still a little heavier. But I'm fine with that. Low pull weight isn't the be all, end all. My Springfield 1911 Mil-Spec had a terribly rough trigger with a jerky release. The pull weight was probably around 5 lbs, but I couldn't achieve better than a 6" group at 7 yards with a junky trigger like that. OTH, I can achieve one hole groups at the same distance with a smooth DA trigger at 10 lbs or more. It just takes some getting used to.
With the lower mass of a J Frame's hammer, stiff springs are a tradeoff to insure reliability to ignite all factory primers/loads.
I have used Wolf springs in some of my revolvers. Usually stick with standard tension for the mainspring, and reduced power rebound spring.
Vito,
Do you make good hits with the gun now? If you do I'd leave it, 640's aren't target revolvers and the pull weight S&W puts in them reflect that. You may want a qualified gunsmith to do an action job on it and try a reduced power mainspring for the time being but I'd leave the rebound weight as is.
Do you make good hits with the gun now? If you do I'd leave it, 640's aren't target revolvers and the pull weight S&W puts in them reflect that. You may want a qualified gunsmith to do an action job on it and try a reduced power mainspring for the time being but I'd leave the rebound weight as is.
I have heard that trigger job on small j frames can resolt in light primer strikes. Since the hammer in that gun is so light to begin with
jad0110 said:
SorenityNow said:
It's not the weight of the hammer, but rather the length. In fact, reducing hammer weight helps reliability by increasing hammer speed and the power of the strike.
In contrast, reducing the length of the hammer to fit the j-frame robs the hammer strike of some force unless compensated by stiffer springs. Compounding the problem, leverage works against the j-frame at other points in the action as well. A double whammy.
I'd recommend dropping the spring weights a bit only if done as part of a good action job by a competent revolver smith. A rough action can rob the hammer of oompf it badly needs, so installation of lighter springs may quickly lead to unnecessary reliability issues.
The 640 has an internal hammer, so it's already relatively light, but a good revolver smith can likely trim a little mass from it (the farther from the pivot, the better) to lower it's Moment of Inertia further. Lower the MoI, and hammer speed increases, so can regain some of the power lost with a spring change.
I like the trigger on my 640 and noticed it has gotten smoother with time and rounds.I don't carry mine in my pocket but have a versa max holster from milt sparks that makes this my favorite gun to iwb.
Guys...
The engineers at Smith & Wesson, as well as other manufacturers would use lighter springs if they thought they could do so without compromising reliability - in any environment, with the revolver in any condition, using any ammunition.
Of course you can install lighter springs, and usually get away with it. Without question you're revolver will work... Until it doesn't. "Usually," and "until" aren't good enough in a serious weapon.
A professional 'smith can smooth the action and cylinder to make the pull feel lighter. Reduction of trigger pull weight through reducing friction is a plus-plus. Screwing with the springs can eventually lead you to a loud CLICK!
The engineers at Smith & Wesson, as well as other manufacturers would use lighter springs if they thought they could do so without compromising reliability - in any environment, with the revolver in any condition, using any ammunition.
Of course you can install lighter springs, and usually get away with it. Without question you're revolver will work... Until it doesn't. "Usually," and "until" aren't good enough in a serious weapon.
A professional 'smith can smooth the action and cylinder to make the pull feel lighter. Reduction of trigger pull weight through reducing friction is a plus-plus. Screwing with the springs can eventually lead you to a loud CLICK!
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