It is what it is, the gen 4's have a duel recoil spring for just that reason; to reduce felt recoil. If you change the spring for a lighter or heavier one the gun could short cycle and have FTF issuesLooking to decrease recoil of my gen 4 G17. I have been looking at tungsten rods at glockstore.com, but they all have mixed reviews. Any reputable brands? Looking to put good parts in my gun so price is not a concern.