+P is higher than normal preassure
+P+ is way higher than normal preassure
i.e. the .38 Special: the store-bought loads are safe to use in most modern firearms.
The +P loads are for use in more recent, stronger firearms.
+P+ can be damned hot.
"I am wracked with such hearty guffaws that in addition to rolling to and fro on the floor, my posterior has separated itself from my body."