Guys:
If you want +P+ loads that are not over pressure, just get Hodgdon Longshot Powder.
I use Factory Hydrashok ammo as carry simply because of the liability of using handloads. However, for home defense, I use 180 Gold Dots with Longshot. In a 4" barrel, I am getting
180 gr 1099 fps ES 24 and consistently under 1" @ 25 yards.
With 135gr 1468 fps ES 39 best groups 2" @ 25.
With 155gr 1307 fps ES 21 best groups of 2" @ 25.
With 165gr 1195 fps ES 25 consistent 2" @ 25.
Hodgdon website lists much higher velocities than these, but the 180 gr loads I have are mid-range 10MM loads. So if there were standards for a +P loading, it can be done quite easily by overloading this powder.
Regards, Shoney