I am gearing up to start reloading for my new .223. Up to this point I have always fully full-length resized all my bottle-neck cases but thought I may try something different with the .223. I have frequently read over the years that it is a good idea to adjust your full-length resizing die not to bottom out against the shell holder for reloads that will always be used in the same gun. I have also read somewhere that a good rule of thumb for doing this was to place a matchbook cover between the bottom of the resizing die and shell holder when adjusting the die. Is partial sizing (and also the matchbook cover bit) a sound practice or just a lot of bull?
Now don't start talking neck-sizing dies here as I intentionally did not get them on the off chance that I (or maybe my son for whom I reload) would get another rifle in the same caliber.