WHAT DOES HODGDON US 869 POWDER CANADA MEAN?

A true magnum spherical rifle powder, it is great with hefty bullets in significant, overbore rifle cartridges. US869 can be a dense propellant that allows the shooter to implement sufficient powder to develop highest velocities in cartridges including the 7mm Remington Ultra Magnum, 300 Remington Extremely Magnum, thirty-378 Weatherby Magnum and O