Basic question on +P loads

[monotonous_iterancy]

I hope you'll pardon my ignorance, but I see +P loads for .38s and such, and I get it means that it's a more powerful round, but does the P mean "powder" or "power"? Also, what's up with things like ++P or +P+? Is that just a general term, or does it denote something specific?

 

[Jim Watson]

+P means "more PRESSURE."
Most calibers for which there is a SAAMI standard, +P represents about a 10% increase in maximum chamber pressure. If the loader chose the powder and bullet wisely, that will get you about a 5% increase in velocity and a 10% increase in energy versus a standard load.
If he did not, all it gets you is 10% more blast and 10% more wear and tear.

If there is not a SAAMI standard for +P in a particular caliber, then it is just advertising and may get you an unknown overload.

+P+ is a marketing term, there is no industry standard. The main use is for government agency sales for which the loader can get a waiver from the cops against accelerated wear on their guns by overloaded ammunition.

 

[ArchAngelCD]

Like said above, the +P means +Pressure.

I totally agree that +P+ is a marketing ploy and might mean the ammo isn't safe for use in some handguns. When you push the pressures above standards the guns were built to, well you can figure out what can happen...

 

[rfwobbly]

Be very aware that not all guns can handle +P ammo. If you have an older S&W pistol it may not be rated for the higher pressures and could be damaged. If your 38 is rated for +P, then it will usually be stamped on the barrel with the caliber and other nomenclature.

 

[788Ham]

I've got a Colt Cobra, 1957 manf. that says on the barrel, ".38 Spl." , thats what will be shot in it. This revolver is like new, picked up at a GS a couple of weeks ago it absolutely shoots like a house afire, very, very accurate piece.

 

[ArchAngelCD]

I've got a Colt Cobra, 1957 manf. that says on the barrel, ".38 Spl." , thats what will be shot in it. This revolver is like new, picked up at a GS a couple of weeks ago it absolutely shoots like a house afire, very, very accurate piece.

BUT, most .38 Special +P commercial ammo on the market today is no hotter than the "normal" .38 Special ammo available when that revolver was produced.

Current .38 Special pressure limits, 17,000 PSI
Current .38 Special +P pressure limits, 20,000 PSI

Most commercial .38 Special ammo on the market barely approaches 15,000 PSI and the +P stuff on the market barely breaks 17,000 PSI with some at higher pressures but not usually above 18,000 PSI.

I'm not telling you or anyone to shoot +P ammo in your gun, these are just my observations...

 

[kingmt]

I don't know if I should mention this but if you stress the cylinder the cases will stick long before it blows. The back strap on the other hand is a whole other story. It would depend on how much it is already worn. Each time you shoot it will get weaker.