+P vs. not: Which handguns

[WheelGunMan]

I checked all my handguns -

Ruger SP101 .357 - it doesn't care

Ruger LCR .357 - it doesn't care either

Ruger Security Six .357 - it has never cared

[Mackie244Bud]

FYI:
On the P365 description page at Sig Sauer States:
Rated for +P 9mm Ammunition

[Laz]

In 9mm, I’m generally one who uses standard pressure, though not always. In .38 Special, it depends on the revolver being used. What I find interesting about this discussion, which seems tilted in favor of standard pressure ammunition, is that a great deal, even a preponderance, of self defense ammunition in 9mm is Plus P and nearly all .38 Special self defense ammo is Plus P. Clearly someone believes modern guns can handle at least a modest or minimum diet of Plus P ammunition. That said, the caveats make sense to me: a steady diet of higher pressure ammunition will increase the amount and rate of wear on the firearm. So will jack rabbit starts and high speed cruising cause increased wear on an automobile. Some pistols, like the Ruger American, are so clearly overbuilt for the cartridge that the company’s blessing on sustained Plus P use is not at all surprising.

[Koda94]

I actually find it highly annoying that stores stock only or mostly +p ammo choices in self defense ammo. I actually wont buy it, not because im worried the gun cant handle it but because it makes no sense to me to rely on something that behaves totally different than the normal pressure ammo I practice with. But the stores stock what the majority of the people want, not whats best as the majority are still believe in "stopping power".

[HiBC]

I generally practice with standard pressure 9mm white box.
I'm not pursuing +P for my S+W M+P 9C

But I do have a question to consider. Many duty/carry guns were designed to handle 40 S+W,as,for a while,it was "the" duty/carry round.

I just looked and the SAAMI max pressure (Not + P ) for both 9mm and 40 S+W is 35,000 psi.
I don't know the exact engineering/physics of how it works out in a firearm,but for hydraulics,at the same pressure,a larger bore cylinder generates more force.
I went off bullet diameters,because I did not have to look them up.It was easy.
The 40 S+W has about 12% more bullet base area.
All other things being equal (they seldom are) I don't think a handgun like the M+P would know the difference between a 40 S+W round at 35,000 psi and a 9mm +P at 38,500.
Of course,the life of a 40 S+W might be shorter.

[JDBerg]

I don’t subject any of my firearms to a steady diet of +P ammo, but every so often you really need practice with this ammo if you carry it!

[Hammerhead]

HK USPs are rated for +p+ in 9mm and 45