I am still experimenting with propellants and charge weights for handloading for the KelTek, which due to it's unusually small size and weight seems to be more sensitive to changes in propellants and charge weight than a full size .380 pistol that I also load for. I'm now using 3.2 grains of Winchester 231 with 100 grain cast lead bullets and it seems to be the best combo I have tried so far for plinking and practice ammo. The same weight of AA#2 also works well. I only load practice and/or plinking ammo with the lead bullets and save the few factory loaded HydroShok rounds I have left for carrying, so I don't try for maximum velocity from my reloads. I don't have a chronograph but the loads I am using now penetrate 3/4" pine boards almost as well as the 95 grain FMJ ammo from Yugoslavia that I found right after I bought the KelTek. I wouldn't use my handloaded ammo for carrying unless it was all I could get, but I believe it would be equally as effective on human targets as factory FMJ if necessary.
BTW, if you try handloading for your KelTek be very careful to set your seating die for the correct bullet seating depth to get the overall length that SAAMI specifies. I had mucho problems with mine until I got that set up right, even a round .004" too long will bind up the slide of my gun. I don't have that spec handy, but if you use a factory cartridge to set the seating stem you should be OK. After setting the seating die to give the specified overall length and a tight taper crimp mine have functioned perfectly so far. (fingers crossed)