PoorShot300 wrote:I can't say definitively they were from the one rifle, it was an online purchase, and the seller just said the rounds went through an AR-15 so it might not have even been military...
Guess I'm good to go and just FLS them all, then weight batch them for refilling. Gives me a chance to get the press set up and the cases ready while waiting for the rifle to arrive.
If they went through a civilian AR15 then most likely a contract shooter using commercial brass.
Don't bother weight batching brass, complete waste of effort. The only way to have consistent volume is to measure their volume. If you are shooting 1000m competitions you may want to, otherwise don't bother. Lots of people don't even bother ensuring their brass is all the same brand.
I would wait until you have the rifle before sizing your brass, unless you're happy to build them to factory spec. To ensure they'll work in your rifle you basically have to size them down to the minimum specs if you don't have the rifle to work with.