I should probably know this but I don't,for the life of me I cannot remember what it means someone out there help a brother out and remind me what it means,please?

+p means high pressure or hyper. usually a +p load is loaded hotter than a standard load in the same caliber. You need to make sure you firearm can handle the hotter loads.

It means hold on extra tight to your 2" revolver when you pull the trigger.

+P means plus pressure. SAAMI sets the maximum average pressure limits for all standardized sporting cartridges in the United states. Loadings that are loaded to +P pressures are above and beyond what SAAMI sets as a safe maximum average pressure.

For example the standard pressure limits for the standard 9mm Luger cartridge is 35,000 psi. A +P load will generate 38,500 psi. a +P+ load will generate 40,000 psi.

It comes from cartridges that tend to be older. Like the 9mm, 38 special, and .45 acp. These cartridges are pretty old nowadays and the older firearms were not built to handle the kinds of pressures that we can now produce with are more effective powders these days. So the SAAMI specs on these cartridges are lower than what we can really achieve to assure if someone is using an older firearm, it is still safe. So new firearms are made from more advanced metallurgy and can withstand the higher pressures, the owner's manual will tell you if it can handle +p or even +p+ ammo. Basically they put an extra grain or two of powder in there, crank that pressure up further and gain some velocity. So you don't see +p in new cartridges since they were designed from the ground up with the newer powders that we have. But who knows, in the near future we might make more advances and you might start seeing some +p .40 out there!

The .40 is already a high pressure round, I don't think you will be seeing them bump that one up..

One would think that but yet +p 40 ammo. is available.

In a round that can already blow guns with modest bullet set-back....I think I'll pass. I'd never heard of that until today.

The 40S&W is not what I would call a high pressure cartridge. It operates at the same MAP of 35,000 psi. that the 9mm and .357 magnum operate at.

Thanks for the help everybody once I read the first reply I realized that I did indeed know that but had forgotten due to way to many blows to the head in empty hand training.

So in essence it would be o.k. to shoot .38 special +p ammo out of a .357 magnum as the pressure would be close to the same as a magnum round or at least within the safe limits,right?