I keep seeing ammo listed as "sub-sonic". The velocity ratings all seem to be in the high-900 to mid-to-high 1000 fps range1, which so far as I know is normal for center fire handgun ammo2, so is the addition of "subsonic" to the description of the load marketing's answer to the proliferation of suppressors?
I once spent a very frustrating range session with what turned out to be slow .22s which would not reliably cycle a Ruger 22/45, and another with a Grandfathered Thompson M1928A1, one of the few grandfathered full-auto firearms in WA, which would not cycle WWB range ammo, so maybe I'm overly concerned with velocity.
1. The speed of sound being 1125 fps at standard temperature and pressure, which is about all I remember from high school physics, alas.
2. Ignoring hot loads, especially for .357 Magnum, etc.