Underwood Xtreme Penetrator ammunition in 10mm Auto delivers a 140-grain solid copper bullet at 1500 feet per second, generating 700 ft lbs of muzzle energy. The bullet diameter is 0.4 caliber and features a Sectional Density (SD) of 0.125, which describes the ratio of an object’s mass to its cross sectional area with respect to a given axis and conveys how well an object’s mass is distributed (by its shape) to overcome resistance along that axis.
The rounds are loaded into nickel-plated brass cases and contain no lead. As a supersonic round that travels faster than the speed of sound, this ammunition is safe for use in a suppressor. Each box contains 20 loaded pieces of ammunition.
Underwood has engineered this load as a proven round for hunting and designed it to be an effective choice for the ultimate in self-defense applications.
