Felt Recoil
Hello Everyone. I'm brand new here--this is my first post!
I have been a competive shooter for 5 years now. Recoil is something I'm very interested in.
The first thing I have personally noticed with decreasing the felt recoil is the poundage of the recoil spring. You will feel much more recoil with a 21# recoil spring in your 1911 than you will with a 12# recoil spring. Also, decreasing your mainspring will also decrease felt recoil. The problem with decreasing the mainspring is it will affect the reliability of your trigger--if you go to low. The lighter the mainspring, the more light strikes on the primer you will get. 19# has always been reliable for me. 17#'s with (soft) federal primers are ok. With harder primers such as Winchester and CCI, I've had reliability issues with 17#ers. 19#ers always set them off.
The problem with lowering the poundage on your recoil spring is you run the risk of cracking your slide--unless you lighten the slide. I believe this is one reason competitive shooters lighten their slides. I've known shooters to add weight to their guns with tungsten guide rods. This helps control muzzle flip, but I've never known a shooter to add weight to the slide.
Another reason to lighten the slide is speed. You can shoot faster splits with a lighter slide. The gun will cycle faster. F=ma. Force is relatively constant. The force is basically your power factor of the ammunition (i.e. velocity times bullet weight). If mass (of the slide) goes down, acceleration has to go up.