+P ammo is overpressure ammo. Quite simply, manufacturers load +P rounds to higher internal pressures than their specifications traditionally call for. This means upon ignition the load creates a significantly higher chamber pressure. As a result, the cartridge launches its bullet out of the muzzle faster than a standard load could.
There is a group called the Sporing Arms and Manufacturers Institute (SAAMI). This group coordinates technical data and sets standards to ensure safe firearm use. In other words, SAAMI sets the standard for size and loaded pressure in ammo. Reputable ammo makers will work to meet those standards.
What Do You Use +P Ammo For?
The big ammo companies make +P ammo almost exclusively for self-defense use. Typically, greater muzzle velocity delivers more of what some shooters refer to as stopping power. Shooters generally want more energy from a bullet when trying to neutralize a threat so the +P load makes sense.
A faster bullet also maintains a flatter trajectory in flight. This can benefit accuracy. You will have to compensate for relatively greater recoil while firing a +P round, however. So, it might be harder to get follow-up shots on your target reliably.
Should You Use It for Self-Defense?
When it comes to defensive ammunition, a lot of people opt for +P loads as a matter of course. It’s certainly not a bad idea on paper; many police departments and federal agencies carry +P or +P+ in their duty guns.
The additional powder load nets an increase in velocity over standard rounds – though how much can actually vary – with the idea being that a jacketed hollow point round traveling at a faster speed will hit the target harder, penetrate deeper, and the extra “oomph” – due to the increase in hydraulic pressure on the bullet – results in more reliable and wider expansion.
Naturally, the attributes of penetration and expansion are desired when it comes to a defensive pistol round.
However, this comes at a cost. The first cost is in increased recoil. An overpressure round will exert a bit more felt recoil on the shooter (though some of us don’t mind too much) which can actually impede accuracy for some shooters.When a person doesn’t like to shoot a round they tend to flinch or tense up prior to squeezing the trigger, a common reason for pulling shots off point of aim.
IS YOUR GUN RATED FOR US:
Use of +P also accelerates wear on the barrel, the frame and the recoil spring in a semi-automatic pistol, requiring service or replacement of parts sooner than would otherwise be needed. Look for a “+P” stamped on its barrel or frame, check with your weapons manufacturer, read the documentation that it came with, or consult an expert. While firing a +P round in a firearm that isn’t rated for it isn’t likely to blow your fingers into different area codes, it could destroy the firearm. That’s a bummer too.
Firearms are expensive, and we would rather you spend your money on ammunition than a replacement for a weapon that you could have avoided destroying!
Learn more about this topic by signing up for our email list to be apprised of upcoming online discussion groups where you can ask questions of our professional educators in a supportive and open environment.