I second Steveno, the Max was designed to push 180 and 200 grain bullets. Mine shot 180 XTP's much better than 158's and they didn't "explode" when they hit. 1400 fps is about max velocity for the 158 gr pills to hold together. Actually, I use a Saeco 180 gr RFN cast boolit for deer now, big meplat and weight for complete penetration and accurate as the 180 XTP.