Simple Upgrade
I read online guidance from Spencer Keepers not to expect too much from swapping out the stock recoil spring with a silicone recoil spring. I believe this to be an accurate statement. That being said, the spring did further soften an already soft recoil on my M9 albeit marginally. For the price it is hard to go wrong on this purchase and only time will tell if there is an increase in parts wear on the gun.