+P/+P+ designations

[rrc1962]

If a particular powder for a particular caliber calls for a start load of 5.5gr and a max load of 6.5gr, how does the +p and +P+ designation fit in? Would +P+ be equal to the listed max load or would +P and +P+ be a percentage over the listed max load? Lets say I normally load a 230gr 45ACP with an 8.2gr which is right in between the recommended start and max. How would I figure out the power amount for a +P or +P+ round?

Thanks

 

[LVLouisCyphre]

It doesn't. Most load data is for standard pressure rounds. The max is the maximum load to be within standard SAAMI pressure specifications.

For liability reasons, most of the load book or data publishers will not publish +P(+) data. They're already putting their neck on the line by publishing standard pressure data.

You can find +P data online, but be very cautious as .1 grain can turn your hot round into a grenade.

Here's a wikipedia article on overpressure ammo with some links to some additional information.

You can also google 45 acp +p load data and find some that way.

I reload to get the maximum life out of my brass while getting reasonable performance in practice rounds. After all, I am just putting holes in paper. If I was reloading handgun hunting rounds or personal protection ammo because of a disaster situation where I am low on personal protection ammo and can't buy more factory ammo then I may be a little bit more concerned about squeezing as much fps as possible out of my rounds.

 

[govtmodel]

How would I figure out the power amount for a +P or +P+ round?

Thanks

You can't. SAAMI publishes a standard that tells what the pressure limits are for normal loading and for +P. Last time I asked them, there was no Standard for +P+. That designation meant only that that the ammunition would develop pressure in excess of +P.

 

[rrc1962]

You can't. SAAMI publishes a standard that tells what the pressure limits are for normal loading and for +P. Last time I asked them, there was no Standard for +P+. That designation meant only that that the ammunition would develop pressure in excess of +P.

Thanks guy. I don't want to load +P, I was just curious. There was a guy at the range shooting what he claimed to be hand loaded 9mm +P+. It got me thinking. I'm perfectly happy with my normal loads for practice.

 

[wolfhunter]

As it was explained to me, "+P" is ammo at SAAMI max pressure. "+P+" exceeds this, so the guy at your range merely needs to go .1 gr over a 9mm max load for a given powder to claim "+P+". As Netentity said, that .1 gr can turn a hot round into a grenade.

 

[LVLouisCyphre]

That's exactly it. There's no SAAMI spec for +P+ and never will be. All it means is that it's hotter and higher pressure than +P. IMO, it's not worth the hassle of playing in the +P or +P+ spectrum unless you have a firearm that requires hot loads such as a submachinegun that is tailored towards hotter rounds.

 

[wolfhunter]

+P+ in a polymer or alloy framed gun is probably a bad idea, too.