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?

Greetings @Hugh Shields,
In addition to what @Oldbloke has said above I suspect that your Super cases are quite old. You could try loading a small sample and firing them to see if you get neck cracks on the first firing. If you do you might want to fire the primers and anneal the cases before your first load. Close to 50 years ago I had problems with neck cracks in Hornet cases in what I think were Winchester Super cases. You also might want to do some check weighing to help with your batching as Hornet cases have varied with weight over time.
Regards Grandpamac.