Sports Master® handgun bullets are engineered to provide consistent, reliable expansion over a wide range of velocities. Sierra has added a serrated "Power Jacket" on hollow cavity and hollow point bullets. On impact, the "Power Jacket" expands uniformly along the serration lines for consistent weight retention and maximum energy transfer.
1911, Issue:11, Page:070
Big Book Catalog, Issue:67, Page:523
Sinclair, Issue:5A, Page:101