Shot my first whitetail with the 63 gr SMP with a .22-250 WBY Varmintmaster. Worked perfectly. No exit, pulped lungs. Would probably work well in a .223, too.

We used that bullet loaded to nearly 3700 fps from a 27" 40XB .220 Swift on woodchucks and crows to 400 yds plus. Worked fine there, too. Less wind drift vs then available 55s. An underrated bullet, for sure. About as accurate as anything else Sierra makes in .224".