I'd try a different bullet. Generally speaking higher BC bullets group tighter at longer ranges v. 100 yds. That's been my experience anyway. I love platinum tips in my Knight extreme and although they shoot sub inch at 100 ydsthey will not group acceptably at 200 yds. In contrast, my T/C Omega will group 245 gr Spitfires sub inch at 100 yds and just under 2" at 200 yds. The Spitfires are higher BC than the PT's. That's just one example but most of my rangework confirms it.