I've got one in .243 also. I shot a few boxes of the cheap blue box Federals when I first bought the gun, but recently decided to try the 85 grain Sierra loading from Federal. My rifle put three of them into 5/8" center to center, and I packed it up after that first group. Might wanna give that load a try.

Also, the trigger is easily adjustable. You might wanna have a gunsmith do it for safety's sake though.