I would try a better brand of shell. Federals are about the worst shells there are. I have the exact same gun, and ordered a TruLock .585 that should be here tomorrow, but was excited to shoot the gun when I first got it, and the factory full and Apex threw a great pattern that I wouldn't hesitate to hunt with. It looked similar to your .570 pattern. I did also just order some Sattie's 2 3/4" 9.5's that I'll be trying soon