Is it a brand new gun?

Did you follow any "break-in" proceedures?

I shoot 1 round, clean barrel thouroughly with copper solevt.
Repeat this 3-4 times. The shoot 2-3 rounds and clean. And repeat this a few times.
Reason I'm told, "The machining of the rifleings creates burrs and these burrs need to be taken down by sending a projectile through the barrel." Sounds simple, but may help. I also only shoot premium rounds. My gun really likes the Winchester Supreme AccuBond's.