Power Pro™ 300-MP (Magnum Pistol)

Last reviewed: 2026-04-17 by Jake Terry, FFL07/SOT3, NRA-certified firearms instructor.

Power Pro 300-MP is a smokeless spherical magnum pistol powder designed for reloaders working magnum handgun cartridges where maximum velocity is the objective. Spherical propellants meter more uniformly than extruded stick powders — you get shot-to-shot consistency across long reloading sessions on progressive or single-stage presses. The improved density of 300-MP allows reloaders to duplicate certain factory magnum loads without exceeding safe case fill ratios, and the burn rate sits in the magnum pistol range, delivering full powder ignition in cartridges like .44 Magnum, .454 Casull, and .460 S&W. Manufactured in the United States, 300-MP undergoes lot-to-lot quality control to maintain consistent energy content and burn characteristics. Secondary applications include the .22 Hornet rifle cartridge, where the faster burn rate and metering precision benefit small-capacity varmint rounds.

Performance Profile

Spherical powders flow through powder measures with minimal bridging or clumping. 300-MP’s ball geometry produces repeatable charge weights on volumetric measure throws, reducing the need for trickler adjustments during high-volume reloading. The magnum classification indicates a slower burn rate than standard pistol powders — full case capacity utilization in large magnum cases without dangerous pressure spikes. Reloaders report that 300-MP enables duplication of certain factory defensive and hunting magnum loads when paired with published load data from recognized manuals. Always cross-reference published minimums and maximums; start at the minimum charge and work up in 0.3-grain increments, watching for pressure signs. The powder’s energy density supports high-velocity projectiles in large-bore revolvers and hunting handguns. For those loading gun powder across multiple calibers, 300-MP occupies the magnum pistol niche — not a one-size-fits-all propellant, but a specialized tool for heavy bullets at high pressure.

Specs at a Glance

Reloading powders require careful component matching. Consult current published load data from recognized sources — never exceed listed maximums, and always start at the minimum charge. Magnum primers are typically required for full ignition of slower magnum pistol powders.

Who It’s For

Handgun hunters loading .44 Magnum, .454 Casull, .460 S&W, or .500 S&W will find 300-MP delivers the velocity needed for field performance on medium game at handgun distances. Silhouette shooters running heavy bullets in magnum cartridges benefit from the metering consistency during match prep. Reloaders duplicating certain factory magnum defensive loads can achieve comparable velocities when following published recipes that call for this burn rate. For .22 Hornet rifle shooters, 300-MP provides an alternative to traditional stick powders in that small-capacity varmint round. If you reload standard-pressure pistol cartridges (9mm, .40 S&W, .45 ACP), faster powders are more appropriate — 300-MP is purpose-built for large magnum cases.