I just a 257 hp raptor from my uncle. He bought this a while ago and shelved it because it had so many issues. The air cylinder was actually pushing the barrel upwards, and it wouldnt hold air. Also it didnt come close to the power they claimed out of the box. I have spent the last 5 days rebuilding the rifle tring to fix all the problems. I was able to get the power up from 80 FPE to 120 but it's still off the 160 that its supposed to make. Now the reg guage is leaking and the outer valve o-ring is leaking. I love all the tuning options just wish it would hold air and make the power its supposed to. When it works its amazing I love they way this thing shoots. Just wish did have to tair it down every day tring to fix leaks