I'd second trying to shoot at 25 or 50 yards until you get a tight group at that range before you back it off to 100.

The other thing I would do it lose the pellets and get some loose T7. Or you can use your BH209, but you need to try more than just 2 weights of powder. I'd start out at 80 grains, then work your way up in 5 grain increments. This takes a long time, but is worth it in the end.

Another thing would be to get say, 3 different types of bullets- maybe some XTP's, Gold Dots, Barnes, etc. Some guns just don't like certain bullets.

Your other option is to send the gun back to CVA and see if they can figure out what's going on.

It took me a long time to find what my CVA likes. I used pellets at first, and was shooting 8" groups at 100 yards. Switching to 80 grains of loose T7 shrunk my groups to 3.5". By playing around with different types of powder & bullets I got that down to 1.5".