The reach to the Kahr trigger is extremely short, I don't know how Joe was able to shoot his.
Practice....and two feet of padded tennis racket grip tape around that stub of a grip on the PM-40.
But Kahr makes 3", 3.5", and 4" barrel single stack pistols that might work for him. I always wanted to try the larger versions in a 9mm instead of the .40. Whatever you do, don't get the .40 in a 3" 17 oz. pistol.
Joe