Winchester spherical powders are known for their
consistent burn rates and clean burning characteristics
and are widely used for reloading shotshell,
handgun, and rifle ammunition. A true magnum handgun powder, 296 was developed for full loads in 357 Magnum
and 44 Magnum, providing high velocities at allowable pressures. Also ideal for 410
shotshells, particularly when duplicating Winchester AA loads.
Sinclair, Issue:3A, Page:103