In 1967, the U.S. Navy type-classified Super Vel's 9mm subsonic 158 gr. FMJ as the Mk 144 Mod 0 ammunition, designed for their Mk 22 Mod 0 "Hush Puppy" pistol. We have duplicated the ballistics with the same bullet at the Navy's specified 965 fps velocity. This load was necessary to replicate the recoil impluse of standard 9mm ball so that even with a suppressor attached, the Mk 22 pistol would still cycle reliably. The 158 gr. Hush Puppy load is specifically made to cycle suppressed pistols with the original factory recoil spring whereas our similar 147 gr. subsonic load may require a reduced-power recoil spring to cycle with a suppressor.