Ammo Basics 101: What does +P mean on a cartridge headstamp? +P+ ? Are they safe to use?

*** PLEASE be sure to read your owners manual to ensure that you choose the proper ammunition for your firearm.  So…for those of you that are trying to shoot .45 ACP ammo through  your Ruger LC9s, please do us all a favor and, as quickly as possible box the firearm up, take it to the closest pawn shop, and take the first offer!!!  But seriously though people… PSA rule of thumb:  Match the cartridge headstamp with the stamp on the firearm with the label on the box of ammo.

Avid shooters will notice the +P designation stamped on the heads of 50 of our new best friends and automatically know that it means these guys are loaded at a higher pressure than standard cartridges of the same caliber.  But, what most shooters don’t know (and will NEVER admit to not knowing!!!) is exactly what that higher pressure is.

Well to quickly explain to all of us (even the ones who already know!), that +P designation was established by SAAMI.  That’s not the Sammy that lives up the street from you who always has the snotty nose, but the Sporting Arms and Ammunition Manufacturers’ institute.  SAAMI is one of the chief organizations in the United States that is actively engaged in the development and education of product standards for firearms ammunition.  As firearms technology advanced (along with all other technological improvements), so did the capacity of cartridge cases to withstand higher pressure loads.  Simply put, to protect those old firearms that your grandfather used (they can’t handle those higher pressures you wacky shooters!), SAAMI developed this designation to identify those cartridges that are loaded at higher pressures.  So the next time you’re out looking for ammunition be aware that your firearm (especially if you’re carrying grandpas 1965 Colt Cobra) may not be able to handle +P loads.

Common myths suppose that these +P loads are loaded “to the brim” with pressure.  This is not necessarily be the case.  Check with your manufacturer to see the differences in pressure loads (often times not extremely higher than that of standard loads i.e. +P .45 ACP loads are usually only in the area of 2,000 psi higher than standard loads).  By an easy side-by-side comparison you can easily determine the difference between the psi of both standard loads and the higher pressure loads.

If you are lucky enough (and in many cases illegal enough!) to have +P+ ammo I’m sure you’re patiently waiting on the explanation for those little guys.  Well Sharp Shooter here goes!  The cartridges that are stamped with +P+ are those that are actually loaded at higher pressures than those specified by SAAMI as +P.  Usually these cartridges are not for sale to the public and only available to LEO.

I must take the time to mention that regardless of the designation be it +P or +P+, higher pressure loads indicate a higher velocity which would in-turn put more stress on your firearm.  My suggestion is that if the firearm is not specifically made for these loads, use them as sparingly as possible.  On that point I’m sure many “experts” will be inclined to disagree with me!!!  Please note that this information refers to the ammunition manufacturers that are registered with SAAMI.  So that means if you have some of Uncle Bob’s Re-Loads and there are some designations on them, I suggest either you contact Uncle Bob or you use them as a paper weight!

The first and foremost goal of Peach State Armory is to promote personal firearm ownership safety.  Please ensure that the proper ammunition is used in your firearm by carefully following all instructions indicated in the owners manual.  If you purchased a used firearm and it didn’t come with a manual, most companies offer copies online.  If not found online please consult with the store you bought the firearm from.  If you run out of options contact PSA and we will shoot around and see what we hit (figuratively only people!!!!).

PSA blog posts are in no way the end-all-be-all.  Please, as with anything, do your research people!

And as always…remember to watch your six and stay low

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