- August 15, 2017 at 12:27 pm #46588GoodsteelKeymaster
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I don’t have a S&W to work on just now, but I can describe the important parts and the way I do it and you guys are sharp enough to follow along.
This is like any other performance tuneup on anything you ever want to be perfect. you have to find a path of importance and follow it through.
The double action pull must be done before the single action pull. Understand that.
Take a moment before starting to inspect your revolver and write down some critical information. Check the DA/SA trigger pulls and write down an average for five snaps. Observe carefully the feel of the trigger and the smoothness.
First, you pull the screws, and bonk the grip frame to get the side plate off. Lay the side plate on a piece of chamois cloth (real goat skin please) and stone the area that the trigger return block touches, and the bearing areas for the trigger and hammer pivots. 400 grit is fine, you don’t want it too shiny. Smooth and shiny are two different things and it’s not about “more is better”. This is about doing it exactly right the first time, so listen to me when I say that too smooth is too smooth. Wrap up the side plate in chamois and set it aside.
Next, remove the hammer block, and stone it thoroughly. Set it aside.
Back off the main spring (leaf style) screw and slip the leaf spring out of it’s slot in the frame and unhook it from the hammer. Set it aside, as you’re going to mess with that last.
Go ahead and remove the Cylinder and arm. Wrap them in chamois and set them aside.
Thumb the cylinder release button and cock the hammer back about half way and remove it. Take your 400 grit paper and press a small piece into the pivot hole. rotate it so you burnish the metal surrounding the hole about 3/8″ diameter. Be very careful to keep your work low enough it cannot be seen when the gun is back together. Wrap it up and set it aside.
Remove the trigger return block. (please do this with the correct tool. One slip with a flat head screw driver and you’ll scar the gun, and now you’re going to be firing up the bluing tanks (or calling me to do it for you). Sand the block with 400 grit, but don’t get too happy with it. It needs a fairly tight fit in order to be smooth. Break every sharp edge on it, and use little split rods to hone the spring hole so the spring will slide freely. Set this aside.
Pull back the hand from the frame, and wiggle out the trigger. Remove the hand from the trigger and stone it to remove sharp edges. Do not mess with the nose of the hand at all though. You will throw your revolver out of time. Go ahead and stone the hand slot as well, but don’t do anything to the sides of it. Rather, remove the burrs, and try to smooth up the bottom edge of the slot. Go ahead and replace the trigger and the hand in the gun.
Now, replace the trigger return block in the frame, but use a reduced power Wolff spring. replace the side plate on the gun and screw it down tightly. Work the trigger and feel for grittiness, or binding, or anything that is not like greased glass ballbearings. Remember that this is the first step, and any compromise you make here is a compromise on the entire job. Use your trigger pull gauge as a way to follow your progress. Once you are sure the trigger is smooth and there are absolutely no weirdnesses, and nothing you can do to gain a reasonable return by polishing, go ahead and put the revolver back together (be sure the cylinder runs freely on it’s pin. You’re going to be using your trigger to rotate it, so any resistance will destroy what you are going for here). carefully check your trigger pull. You should notice a huge improvement in smoothness, and some reduction of pull weight. If this is a combat revolver, stop here. You are done. Check function, cylinder gap, cleanliness, and put it into service.
However, if this is a Target revolver, you’re just getting started.
Take it apart again and clip a coil off that trigger return spring. Reassemble. Check for function. Repeat until the trigger starts to only return if you let it go quickly with the revolver fully assembled. Take an identical spring and add 1.5 coils to the length the previous spring was cut to. Check for function.
Remove the mainspring from the revolver, and vice it by it’s bottom edge so it’s pointing at you. Take a sharp needle file, hold the handle in your left hand, and begin draw filing this spring in even, smooth strokes, but do not compromise the tip where the hammer roll track is located. Once you have stroked some metal off, reassemble the revolver. Check your progress with a pull gauge.
Make some dummy ammo by drilling out the flash holes so you have a large hole with enough rim around it to give the primers something to stop on. Prime these with federal and use them to test your action.
Back the mainspring tension screw out one full turn. Shoot 12 of these blanks and go back to filing. Reassemble, check pull weight, back off the tension screw, then shoot 12 more and repeat.
As soon as you get a snap when you should have gotten a bang, tighten the tension screw all the way down and check your pull weight. Go out and shoot 100 or so rounds. If you get more than 5 misfires per hundred (95% reliability) then remove the tension screw from the frame and hold the nose of it in your lathe or cordless drill and file the underside of the head to allow it to screw deeper into the frame applying more tension to the mainspring. Remember that your fulcrum on the mainspring is very short, so a very small change in this screw length makes a big difference in pull weight. Check your progress with the pull gauge. Remember that at this point, your trigger pull is directly associated with how hard the hammer strikes the primers, so you must witness a significant change in order to effect the reliability of the gun.
Go back out and shoot another 100 rounds. If your FTF percentage drops to 1% or less, put a fork in it. If not, work on that screw some more, but stop when you start getting close to the drive slot. If you’re off that far, then you were ham handed and did not test enough when you were draw filing the mainspring. If this is the case, replace it and start over.
Once this is completed and you are sure the double action pull is as perfect as you can possibly make it, you can start on the single action pull. For this part of the job, I highly recommend the Power Custom stoning jig, proper stones, and a strict adherence to the instructions. I will give a detailed tutorial on how to do single action trigger jobs one day, but if you follow my directions above, you’ll find that the single action pull of your revolver is greatly improved, and may need nothing to suit your tastes. However, it is very possible to have a 5lb double action weight and a 12oz single action weight.
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