Look into the Wolff Powerib Mainspring. Maybe a rebound spring too. Take the side plate off and hose it down with cleaner and re-lube lightly. Will take you 20-30 minutes. Give it a try!
And as long as we're talking about springs, my father-in-law's M&P was bought new in 1920, carried daily in the hip pocket of his overalls for 60+ years, and somewhere along the way was treated to a rebound slide spring replacement by Bubba. The spring seems to have been selected on the basis of the fact it fit in the hole, and resulted in a DA trigger pull of 22 pounds.
Now I'm not much on hosing things down with cleaners from spray cans, so I removed the sideplate and everything inside it, put it to soak in Mineral Spirits, and made everything squeaky clean. I'd heard about these "Spring Kits", so I got one of those from Jerry Miculek (BANG, INC.).---2 springs and a set of instructions for maybe $20. (I've been messing with these things for about 60 years, so I didn't bother with the instructions on how to install a rebound slide spring and a mainspring-------and nothing would move when I finished.) There's an old saying about reading the instructions when all else fails, so I gave that a try.
The bottom line of all this is you can send your gun off to a big name gunsmith, and it'll come back slicker than greased Owl do-do with some shiny pieces that didn't use to be shiny, and it will only cost you somewhere between $100-$300. As an alternative you can spend that $20 I noted up above, READ and follow the instructions like I finally did, and end up with a gun that's slicker than greased Owl do-do (but without any shiny pieces).
There's some measuring and cutting involved, and Miculek recommends you don't go any lower than 7 pounds on the DA trigger pull, lest some primers won't pop, so 7 pounds it is, and everything works----slicker than greased Owl do-do----and goes bang-bang-bang any and every time you want it to do so.
I'm all for sending stuff off to an expert for repairs, or making stuff you can't buy, but the installation of a Spring Kit----even Miculek's, is brain-dead simple.
Ralph Tremaine
