I tried the JP springs in my JR carbine rifle. I also put in KM tactical's flat trigger. I left all the rifle's guts the same, I just replaced the springs and physical trigger.. I have been having issues with the rifle randomly bump firing. RO's look at you strangely when your rifle goes boom boom instead of just a single boom at a match. I'm going to put in a Hiperfire trigger today. I've always had good luck with their stuff.