I ran into a situation on my new Condor and wanted to possibly help anyone in a similar fix. My condor did not want to group consistently with anything I tried. This gun has the different orifice changeable tophats. The closest I could come to it's doing right was with NSA 33.75slugs at 1000fps. The group would move from right to left at the slightest change in tank pressure. Well I decided to change to another tophat and discovered the two pieces were not tightly wedged together and would freely rotate on the threads. I find it hard to believe that this small amount of air escaping could cause this problem, but upon tightening this and adjusting properly, now the gun will group well with just about any projectile I feed it. There is an o ring between these two pieces so apparently Airforce realized this may cause some difference.