What is +P on this ammo — 1 Answer

+P ammunition is the highest chamber pressure cartridge that may be fired in a particular weapon.
The Ammunition Pressure Levels are standardized by the SAAMI.
Which is the Authority that dictates the safe operating chamber Pressure for each caliber, factory.loaded.
+P ammunition is factory.loaded to maximum chamber Pressure, in order to Provide The maximum velocity, through maximum Pressure allowed by The SAAMI.
THE STANDARD-ARMS-AMMUNITION-INSTITUTE.
RELOADED AMMUNITION CANNOT BE APPROVED BY THIS RATING OR MISUSE, AS PRESSURES CAN CERTAINLY BECOME EASILY OVERLOADED.
RESULTING IN UNDUE WEAR OF THE FIREARM, OR FAILURE TO CONTAIN THE OVERLOADED FIRING CARTRIDGE, WHICH CAN RESULT OF DEVASTATING FAILURE, WHICH CAN DEVELOP A BLOWN.UP WEAPON.
RESULTING.IN INJURY, OR DEATH TO THE SHOOTER, AND. NEARBY ONLOOKERS.