I am running the jp on a dpms lr 308 oracle. It may have tamed it a bit, but not as much as I thought. I took a little while to get it dialed in. The screw that meters the gas has a tendency to self tighten during long sessions so make sure you index it and check it every few rounds. Maybe there is a way to make it stay put without using a threadlocker of some kind but I have not been successful yet.
Also, I had hoped I could dial the gas back enough that the spent cases would eject close to me and not dent when they hit the deflector, but that is not the case. They do eject less forcefully, but still dent the case just a bit as long as the gas block is open enough for reliable cycling.