I've put the JP spring kit in all my AR's including my 1522. Prior to installing them in the 1522 I was having jams and mis-feeds (2 or 3 per mag). Since installing the JP springs I've not had a malfuction in over 400 rounds. I don't think it's coincidental but rather the bolt cycle is faster. It also provides a light, crisp trigger pull with no other mods. If you ever have to send it to S&W for repair be sure to put the factory springs back in.