cknight98....
The Kel-Tec P3AT instruction booklet indicates (on page 3) that the Kel-Tec P3AT (9mm Short aka .380 ACP) can use +P ammo, but not as a steady diet.
The .380 ACP could be called a "9x17" if you used a European type designation... and with the MAGTECH "Gold" +P 85 grain JHP ammo at almost 1100 fps, the .380 has a muzzle energy of 221 ft/lbs.
Comparatively, a .38 Special using a 158 grain lead bullet has a muzzle energy of 235 ft/lbs... almost the same as the .380 or 9mm Short.
I've carried a P3AT anytime I'm outside the house for almost a full year now... and the more I carry it, the more I "appreciate" the little pistol.
With 6+1 rounds, a very small size (about as small as they get) and a mere 12 oz. (weighed fully loaded on sensitive, accurate scales) in weight, I think it's a fine little carry pistol with enough power to extract your fanny from a problem should one occur.
At less than $300, I think the Kel-Tec P3AT .380 is the hands-down "winner" of the highly concealable, BUT STILL EFFECTIVE self-defense pocket pistols.
Strength & Honor...
Ron T.