Since some some the longer heavier pull is safer, why are most revolver DA pulls so heavy? Why not make them long and 6 lbs? Is it the geometry of the mechanism?

In the double action revolvers (and pistols with DA triggers), pulling the trigger in the DA mode compresses the mainspring to prepare it to be released to drive the hammer or firing pin forward to ignite the cartridge primer. In a revolver with a mechanism like a Smith and Wesson, the rebound slide spring is also compressed by the trigger pull.

It’s possible to reduce the pull weight by making those springs weaker. The problem with doing that, though, is the mainspring may be too weak to fire the cartridges reliably (and can actually affect how precise/accurate the gun is), and if the rebound slide spring is too weak, the trigger won’t reset properly or will reset slowly and limit how fast the revolver can be fired.

As in the SIG DAK mechanism, it’s also possible to reduce the pull weight by increasing the mechanical advantage of the system. That, however, will result in a longer trigger stroke:
“Ye canna change the laws of physics, Captain.”

I've got some heavy, gritty trigger pulls among revolvers; the SP-101 has never been known as particularly great in the double action pull, without some work and springs.

My Kimber K6 operates like a striker fired pistol; short stroke, light, and feels more like a Walther or P320, but short. It functions like a single action trigger, all the time.

My take: if it is a DA/SA revolver, the fear of a 'hair trigger' on the SA pull leads to heavier DA trigger pulls.

The geometry may allow for a lighter DA pull, but at the risk of a really light SA pull.

My 586 has a DA pull that is smooth and crisp, and probably around 7lbs. the SA pull feels closer to 2-2.5lbs.

My Colt 3 5 7 has a similar pull, after a visit to a skilled smith.

My GP100 has around a 7-8 DA and the SA is probably close to 3-3.5.



Now, the Ruger LCR in DA only has a pull that feels smooth, breaks nicely, and isn't over 7lbs, I believe- but it is DAO. They don't have to worry about a hair trigger on the SA pull.

Yes, reducing the spring force that must be overcome when pulling a double action trigger also affects the single action pull force. With less pressure between sear and hammer in many (most?) designs, it takes less trigger pressure to overcome the friction between the two.

At one time there was a SIG factory mainspring marked with yellow paint that was less powerful than the standard spring. It was reportedly used in double action only guns, and what was the reason for that? Because reducing mainspring power also affects the single action pull weight, the SA pull probably became too light for the factory specification requirements, but reducing the DA pull would have been desirable. In my experience with the yellow spring in a DAO gun, however, it wasn’t powerful enough to reliably fire all ammunition. It is now nothing more than an historical curiosity.

Reducing mainspring power has long been a “secret” way of making pull weights lighter and trigger strokes smoother without doing anything else to the action of certain guns. The trade-off is reliability.

Reducing mainspring power has long been a “secret” way of making pull weights lighter and trigger strokes smoother without doing anything else to the action of certain guns. The trade-off is reliability.

After playing with the rebooted Python and their Cobras, I'd say that Colt has figured out that "secret". Amazingly smooth trigger and hammer I must say, particularly with the Python. Perhaps that's why this generation Python has had its reliability issues with the cylinder.

There are surfaces in the action parts that rotate or slide or otherwise bear against one another, and these can be smoothed up and fitted to reduce this friction. This has to be done with great care, but is the best solution rather than making springs weaker.

quote:

Originally posted by sns3guppy:
I've got some heavy, gritty trigger pulls among revolvers; the SP-101 has never been known as particularly great in the double action pull, without some work and springs.

Having done quite a few SP101/GP100/Super Redhawk, cleanups, I love me some Ruger wheel guns. Judicious and careful polishing, springs, and shims, can make a world of difference on those particular guns. That said, Ruger does a terrible job of cleaning up their machining and tool marks. How they got the LCR generally right somewhat surprises me.

All of this to say to the OP, some of the DA heaviness is attributable to design, some not so much.

The double action trigger on a revolver has several jobs. Yes, it must pull the hammer back, and release it forward, but the trigger pull must also rotate the cylinder to align a fresh cartridge or charge hole with the firing pin. One way manufacturers have lightened double action trigger pulls is by using lighter cylinders, such as titanium. Lighter springs, judicious polishing and hammer alignment also plays a big part in the equation.

My DA Ruger LCR 38 trigger as measured on my Lyman trigger pull gauge breaks @ 8 lbs.4 oz. for a five shot average. I have about 600 rounds through it and I do not dry fire any of my guns.

I love the trigger on the LCR and I don’t have any problems with trigger reset