WHAT DOES BULK 300 BLACKOUT AMMO MEAN?

I've often listened to the 110gr was made specifically for the .300BLK and expands at A lot decrease velocities. I feel the bare minimum velocity for enlargement with the 120gr is 1800fps.Heaps of people run subsonics without a can. It could need enlarging the fuel port diameter however. Also utilizing a lighter BCG, lighter buffer, weaker buffer s