I think you hit the nail on the head for this Magtech load. I'd bet advertising hype. Their stated velocity isn't that much above other good SD loads and they are using an 85 gr. bullet where most others use 90-95 gr. bullets.
Originally Posted by Tubby45
They can't just whip out a +P rating for a specific cartridge. It not only depends on the strength of the firearm but also on the strength of the cartridge casing itself. If the design of the cartridge doesn't allow it to hold higher pressures, then that's what you're stuck with. You can see this in some of the +P brass offered by Starline:
Originally Posted by harley2007
45 AUTO +P (Large Pistol primer) .892"-.897" O.A.L. (Backordered expected availability: 08-31-2009 ) While other calibers are the same:
The 45 Auto+P is a strengthened version of the 45 Auto with the same external dimensions. A thicker web and heavier sidewall at base strengthens the case in potentially unsupported areas. This case has approximately 2 grains less internal water capacity than the standard 45 Auto.
9MM+P (Small Pistol primer) .748"-.754" O.A.L. (Backordered expected availability: 09-15-2009 ) Here is a list of SAAMI pressures for most common firearm calibers.
9MM+P has no difference from the standard 9mm Luger other than headstamp designation for load segregation. Due to standard case design, it will handle +P pressures with no problems.
Also, another thing to consider is that the LCP leaves a rather large section of the case unsupported by the chamber. Here is a photo of my LCP barrel with a cartridge:
With that much unsupported case, I'm not putting any of the "hot" stuff in mine. I like my fingers.