Thread: Prepping new brass ?

Originally Posted by Hugh Shields

So GrandpaMac and Oldbloke, I've acquired a couple of hundred brand new, primed, Winchester Super cases in 22 Hornet. The Hornady reloading book states: Maximum Case Length 1.403, Case Trim Length 1.393. A random selection on the new brass measure; 1.399, 1.401, 1.402, 1.404, so I'm guessing I should be trimming (and de-burring) the whole lot back to 1.393 for consistency. I'm trimming all the fired brass back to 1.393, and batching by brand and age as best I can. Some are mixed up purchases. Firstly, I'm surprised that newly manufactured brass have that much variation in length? Secondly, how much is accuracy affected (within one batch at 100 metres) by having variable case lengths?

Hornet can be a difficult case to reload, the brass is thin and needs to be handled carefully to avoid crushed cases. I doubt that the range of lengths you have which are all within tolerance will result in any noticeable accuracy variations but remeasuring after firing and then trimming could be warranted it "grows" on firing a bit more than most cases do.