If weight isn't much of an issue, and IF you can find the ammo, you could try the Ruger .327 Federal Magnum, 85 grain, in the GP100 Revolver. They have a real good punch on what they hit and I would not hesitate to use one for self defense. These .327 FM guns will shoot any .32 caliber cartridge, although in ACP you will experience some light strikes in all probabilty. I've read that when Federal made this for Ruger, they added the 7 just to separate it from the boys. If you shoot anything other than the Fed Mag cartridges, it's like shooting a .22 LR. I can get a little weak wristed sometimes and this gun never bothers me a bit. Mind you, if you shoot one, use good ear protection; not those foam push-in kind of plugs unless you're putting earmuffs over them. This gun in 6" is 1/4 oz. heavier than my 6" S&W .44 magnum, model 629-6. Good luck.
Most of the .22 Magnum revolvers that I've played with are pretty soft-shooting and cause a little more damage than the LRs. You'll have to check with the ballistic pros about that.