I'm very new to reloading. I've got TONS of equipment (my press is a Hornady progressive Lock and Load) and I have read the MANY reloading manuals that came with my equipment. Regarding all this equipment, it was part of an estate and it was all given to me. I have already made a few thousand rounds of handgun ammo (9mm and 45 ACP) with success. I DO have a few years background as a machinist so most of the concepts are easy to understand. I would have preferred to start with a single stage press, but am not really having any problems with a progressive press. I do go slowly, focus completely, and re-check myself often. I am now trying my hand at .223 reloading. My question has to do with case length. I have cleaned, de-primed, and inspected my brass. I am now in the process of trimming to length (I have a Lyman "universal" hand trimmer with the proper pilot). The "length" is properly set and the case are coming out at my desired length....and I follow that by removing the burr (both inside and outside) HERE'S MY QUESTION: I know that the length may change slightly when I size (full length die) the case. It seemes to me that the case should be trimmed AFTER resizing, however that NEGATES the advantage of a progressive press. Seems to me you can't "progressively" reload if you have to trim to length AFTER re-sizing. Can anyone tell me if I'm correct about this? Thinking about this is driving me crazy. Thanks.