I read / got some tips on extending brass life on bottlenecks. One was neck resize only for same chamber brass. I read lube inside only - very lightly and then resize. And I did, as well as measuring the length before and after - about .004 longer after resize. Today I forgot to lube some cases and the feel on the pull was about the same as with lube. So I did an experiment - 10 with and 10 without lube. The result was that they stretched the same. About .004". Do I even need to care about lube on neck resize only?