my experience with jp parts is they are excellent parts. you can use them and have no issues, but you need to understand how your 308ar works before you set it up. put the lmos in your gun it will last many years, good stuff. the carrier (lmos) is if I recall 8oz lighter than std carrier, and it moves very fast in recoil because of that. so you set your gun up for 150gr ammo and it will give you no problem for many thousands of rounds. you're out hunting and run out of 150's and can buy some 175's, so you load them in your gun and shoot them. because the gas dwell time is longer with heavier bullets you have now overgassed your lightweight buffer system that you set for the 150's. my experience with this system is that before you shoot the 175's you will have to adjust the gas block to lower the pressure to the bolt.