If you don't have a caliper, just collect some old keys, the ones with a factory stamped number are originals, some quicksets may be copies of a different key if they are copies, perhaps wieser or some such, anyway, an original key has five of the cuts represented on it and the spacing is on the old key, so you could cut any original down to its deepest cut, on all the correct spaces, and then you might have a bump key that would work on a lot of locks, even if the deepest cut on it was not a seven You can make a bumpkey without a caliper, Just don't go too deep, as this puts you beneath the pins an you won't be hitting them. Spacing and depth on bump keys seem to have some forgiving tolerances, close counts as good enough on most locks, So figure that you will probably be making more bump keys, that its not a thing you do once and never again, collect old keys, they can be made into bumps, you will have some idea of the spacing and depths from them, and you will have a variety of keyways after making some successfully, you will be your own expert.
