It's new, and has been sitting in the box since he won it at a tournament years ago. So i'm gonna have to go through it and see how the o-rings are. I found a nice list of o-ring sizes and owners manual, so thanks to the folks who put that up. I was planning on running it on hpa, and i have a gas through grip, expansion chamber and reg on standby incase i want to try co2. I will get pics in the picture section once it comes in and gets cleaned up.