Helo Rich
2 years of hard work, fingers cross for you.
No worries about the barrel.
Once you have fitted the BOB, gas up the gun and check for leaks to make sure you have fitted everything together ok. Then if you can not hear any leaks, turn the eyes off and fire the gun a couple of times to make sure every thing if working ok. If there are no leaks works ok when you next go to your local PB site chrono to make sure it is still running at what ever the site limit is. The BOB should not change the FPS, bolts, QEV etc will.
Any problems just PM me for my number and I will talk you through it. As I said when you got the gun, any problems with the BOB if I am up your way I give you a hand.
The BOB will make life a lot easier with cleaning etc.
Enjoy
Anthony