Bumping the shoulder back near as I can tell is FL sizing but sizing to fit you chamber. Neck size till the case's won't chamber any more then start adjusting the die down until the case chamber's easily. You will have FL sized just to fit that one certain chamber. I have 2 234's and both have their own dies set up this way and locked in. Another term is partial sizing, make the case fit the rifle it came out of!
