What do you think of this ammo? Make the .577/450 into the ideal buffalo cartridge?

https://www.midwayusa.com/product/1001932065

Cartridges for cowboy action shooting sports, hunting, long-range rifle competition. Safe and effective for use in first generation guns. Generally more accurate and cleaner than the original factory loads. Made from the highest quality components available.

Technical Information
Caliber: 577-450 Martini-Henry
Bullet Weight: 480 Grains
Bullet Style: Hollow Base Spitzer Flat Point
Case Type: Brass

Ballistics Information:
Muzzle Velocity: 1333 fps
Muzzle Energy: 1893 ft. lbs.
BPC is Hodgdon Triple Seven black powder substitute
Ten-X
warning-iconWARNING: This product can expose you to Lead, which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to - www.P65Warnings.ca.gov.