Ammunition rated +P generates a chamber pressure higher than the cartridge’s published standard, but the level is less than those produced when proof rounds initially torture test a firearm. Increased bullet velocity is the result—an advantage for some self-defense handguns—but not all guns can safely run the hotter loads. In those cases, the added stress can prematurely wear parts, void some warranties or, worse yet, lead to catastrophic failure and personal injury.
Owners of firearms rated for its use, however, can run the ammunition with confidence. Improved performance on target is the biggest advantage. Flatter trajectory is another, although +P is primarily handgun ammo, where reduced holdover at 100 yards isn’t a huge concern. That benefit, however, may be of interest to anyone with a pistol-cartridge carbine.
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