On a 40 S&W minimum trim length is .843". The max is called out at .850". The 40 S&W head spaces off of the mouth of the case. Some of my cases are around .840" -.841". these are once fired factory new. I am warned as to not trim too short, but to keep all batches uniform in length and not to seat too deeply as to avoid over pressure. If new once fired factory brass is coming up short of minimum trim length on a number of cases ( out of 200 about 30 or so ) then do I send the short one's to the copper scrap pile or is - .002 to .003 going to be that much of a problem. Seating the bullet to meet OACL. Thanks up front!