Why would the extra length of a rifle bore snake wear out a pistol barrel? I have several bore snakes, some of pistol and some of rifle length. The difference between the two is that there is a longer section of braided cotton on the rifle vs. the pistol bore snake. That stuff isn't going to wear anything out, no matter how many times you pass it through the barrel. Both the rifle and pistol bore snakes have bronze bristles embedded in the first few inches, but so what? The bronze in those bristles is softer than the steel of the gun barrels, so even if there are a few more bronze bristles in the rifle version as opposed to the pistol, there's no chance that they'll wear out the gun.
I happily use rifle length bore snakes in my pistols. Never had a problem, and I doubt that I ever will.