BROWNELLS - SW-MS-222 MAINSPRING FOR S&W K,L,N FRAME REVOLVER

With my S&W 686-Plus, which is a factory "Supertuned" gun, (model 178029), shooting my reloaded ammunition, I was getting about 3% failure to fire due to light primer strike with the factory spring. The factory spring was so light that even before I ever fired the gun when new, I thought I might have some reliability issues. This "Brownell's" spring is actually a Wolff spring. It is slightly heavier than the ultralight spring that came in my gun from the factory, giving a more confidence-inspiring, though only slightly heavier feel. I'm guessing it may have added about 1 pound to the trigger pull, but reliability has been 100% over several hundred rounds. All in all, I would say, at least in my gun, this is the lightest spring I would install to expect the gun to function every time I pull the trigger. Well worth the money. Considering it only takes about 10-15 minutes to install, what could be a better value in action work? If you don't already have a good set of GUNSMITHING screwdrivers, at least buy a set of gunsmithing screwdriver bits so you don't mess up the screw heads when you pull the side plate off.

Installing this spring along with an 11 pound rebound spring yielded a nice 7 1/2 pound pull with a positive reset in my model 64. The overall feel of the spring is far better then the stock spring which gave me a 9 pound pull. I think this improvement is more then just the decrease in weight. I think the spring is variable so you get more resistance at the end of the pull then the beginning where you have less leverage. This combination and a lot of dry firing will get you most of the way towards a trigger job assuming everything else in the gun is "right". A real gunsmith can do much better (5 - 6 pound range) with the stock springs, but a real gunsmith also costs a lot more and requires you to ship the gun unless you are foolish enough to trust the local guy. Another poster mentioned that he had trouble using the mainspring in his 617. .22 ammunition requires significantly more energy to ignite then centerfire ammunition. Also strain screw lengths are all over the map and on used guns they may have been ground down. You can try extending the length of the screw by placing a spent primer on the tip or purchasing a new screw if you suspect yours has been modified. You can also use a hardware store set screw and loctite. If you don't get reliable ignition with a .22 revo and this spring then you probably need to apply more strain. Don't expect the .22 to ever be as good as a centerfire revo once properly sprung.

Installed it on my Jerry Miculek S&W 625 .45 acp. Would not fire a single round. The spring is so weak I could watch the hammer bounce back after being released. Didnt work on my gun but sure had the lightest double action pull Ive ever felt.

I installed one in my 617. It is too light to reliably fire any brand of ammo I tried. I tried around 10 brands. I'm going to try it in a centerfire.