The Underwood ammo 700grn T-REX rounds. I was expecting harsh, so I definitely was on my game with grip and two arm technique. Absolutely more recoil than my usual 350grn rounds, but not horrible scary. However after five of them I wasn't all that interested in shooting more...LOL
This round passed through a bowling pin and then into a pile of sand. We found that it struck the bowling pin pretty much flat on its nose, so it didn't tumble which surprised me. Five of these totally destroyed the bowling pin.