Howdy
What a great opportunity to try out my new Lyman digital trigger gauge.
Tested four double action S&W revolvers in single action mode, and one Three Screw Ruger Single Six.
The lightest trigger pull was a S&W K-22 made in 1932. 2 pounds, 8.2 ounces.
Next was another S&W K-22, this one made in 1950. 3 pounds, 2.5 ounces.
Next was a S&W Model 17-3 (the updated version of the K-22) made in 1973. 3 pounds, 14.1 ouncers.
Last of the Smiths is the newest, a 617-6 made in 2003. 4 pounds 5.1 ounces.
Just for fun, the Single Six, 4 pounds 2.1 ounces. Like I said, this is an old Three Screw, I don't have a modern Single Six to test.
This pretty much bears out what I have always felt. When shooting several 22 revolvers for comparison, after shooting the others, it felt like a feather could trip the trigger of that old K-22. But you may not be able to find one. The Model 17-3 is still no slouch at 3 pounds 14.1 ounces. These guns were made in the era when parts were hand fitted, so it should be expected they will have very good triggers right out of the box.
Not so with the Model 617, hand fitting parts had ceased by then.
With a Ruger you are going to have mass produced parts that are assembled without any hand fitting. Wish I had a modern Single Six to test for you, but I don't.
I can say though, that I have put those Power Custom parts into three 'original model' Vaqueros, and they all have trigger pulls around 2 1/2 pounds. On one of the Vaqueros I had to do a teeny bit of filing, the other two were straight drop in with no fitting at all. The kit consisted of the Power Custom half cock hammer, matching trigger, and a lighter main spring and trigger spring. The beauty of the Power Custom parts is they are cut on wire EDM (Electro-Discharge Machine) not CNC, and the parts come out with a terrific finish, better than the original Ruger parts. So not only are the springs lighter, but the full cock notch and sear are smoother than stock, so there is less friction. That is my experience with Power Custom Parts in Rugers.
But for a terrific out of the box single action trigger, it is hard to beat a S&W K-22 or Model 17 made before MIM parts.