I don't know if you have a Chrony, but your rifle could be shooting these lighter pellets to fast? That would cause the larger groups. In that case move up to the 10.3 grain JSB's
Most of the FT shooters I know shoot JSB or Air Arms pellets. H&N too. If you buy Crosman pellets they will need some serious washing and sorting and weighing and relubing? But there are a few that have success with them.
I shoot the 13.4 gr .177 JSB pellets in my Thomas right out of the tin with much success if that gives you any idea how much I trust them. Of course you would need your speed adjusted to shoot them if your gun liked them?
I would highly recommend getting a Chrony as the 8.4 and 10.3 gr pellets like to be shot around or just below 900 feet per second. I shoot the 13.4 gr monsters around 820 FPS.
Finding the right pellet and the right speed for that pellet is the key to tighter groups.
I love this Chrony, and I used to have the high dollar Labradar!
Had a friend who came over and shot across it this weekend and he has the Labradar and said he should sell his Labradar and get the G2. He really liked it.