It seems that the 80gr Fort Scott TUI projectile is pretty capable against soft body armor. The youtube channel Buffman Range tested this round against AR500 IIIA hybrid armor out of a 4.95” barrel and a 3.6” barrel.

https://youtu.be/S09LMYAmnjA

The round penetrated the armor from the longer barrel but failed to do so from the short barrel. This would seem to indicate a penetration threshold of roughly 1300 fps. However, the AR500 hybrid panel is tougher than typical IIIA soft armor since it has UHMWPE. Does anyone know what the penetration threshold would be against standard aramid IIIA armor? I’m sure it’d penetrate at muzzle velocity out of most 9mm pistols, but I’m curious about how the penetration range will change between barrel lengths.

The issue is that NIJ standards are min, and many company's will build in a little extra safety margin. This bullet is pretty hard to stop. I use it when I'm testing rigid IIIA panels, because most soft PE or Aramid can't stop it.