Winchester Smokeless Powders have been around since the late 1800s. Customers that have shot Winchester factory loaded ammunition know the quality of propellant they’re receiving as soon as the first shot is fired. Bring that quality home to the reloading bench with the Winchester family of powders. The Winchester 296 powder was developed for the 357 Magnum and 44 Remington Magnum cartridges. Winchester also recommends this propellant for use in 410 Bore AA loads.