When I had my Sig 229 .40 S&W (which I just bought another one) I used a Sprinco recoil reducer in it... The unit worked well, at making the sharp recoil of the .40 S&W more like a .45, i.e. more rolling like... Felt recoil is a subjective matter to begin with, but the use of the Sprinco unit made it seem like the recoil was reduced... Personally though, I think one of the best things about the product is that the secondary spring slows the slide down at the end of travel and helps to decrease the battering between the slide and frame (hence longer frame life).