Barrel alignment

My neighbor down the road bought a used .22 Vulcan a year or so ago. It had two different owners before he bought it. Being he goes to Florida every winter and can’t shoot it where he stays, he’s had little time to tinker with it. Well it came with a Reg tester so he checked the regulator and it was 105 bar, BUT, it was shooting all over the place, lows in the 500 fps highs in the 700 fps, so he rebuilt the reg and found a bad o-ring.
He cranked up the reg to 129, per Ernest to get in the upper 800s, but was only getting 730 fps and couldn’t figure out why. So we brought it in the barn and compared it to mine and found that the barrel set screw wasn’t even in the barrel aligning hole. Also the barrel was rotated about 1/4″ off and the end of barrel was flush with the action where as mine had about 3/16″ protruding. So we loosened the clamp screws and rotated the barrel and pushed it back so the set screw was back in the barrel where it should be and Holly Shit what a difference!
Took it back out to my Crony and tested it. First mag was 907 fps for damn near the whole mag, second mag was just about the same, 22 shots with a spread of about 3 fps. Being the barrel was rotated and not aligned properly the air flow was affected which caused the lower velocity. He’s like a kid with a new toy now and I bet he’ll be going through a ton of pellets now.
If your is shooting all over the place, velocity wise, check your barrel alignment that may be the cause of your problem.

Zonk