Recoil spring

If it's the pro cut slide you have. Sig says that the Pro Cut slides are generally the same weight as the standard slides, size for size. They just don't mill inside the slide for weight like they do on the standards. So your OEM RSA will be fine.

I've asked Sig about it and its supposed to be the exact same weight. If you look on the inside of the slide towards the back you will see that it doesn't have the internal cutouts to balance out the cutouts in the front.

For full size pistols I love the Springer Precision tungsten guide rod with 15 lb 1911 spring from Nighthawk Custom. If you have a smaller slide, the DPMS system is your other option.

Good to know thanks