T7 in its basic form is white and almost smokeless but not progressive; that why after you get to a certain amount of powder for a given caliber it will add to the pressure but not the velocity. That's because the powder that does not get burned in the barrel still adds weight just like the bullet does, they tried to get around that fact with the extended breach plug so the fire burns in both directions from the middle but I have heard complaints about the eroding barrels right where there fire starts. Lee