As many of you have probably read I have been working to put together a cartridge for my newest contender build. I loved the idea of the 30 badger but wanted to use 357 magnum brass to have a little more power. I ended up running the 357 magnum brass through the 300 blackout fl die. What i ended up with is a rimmed 300 blackout that is about .075 short in the neck. my question is do I have MGM just chamber the barrel for a standard length 300 blackout and have a fairly large jump with 125 grain bullets ( I suspect over .100 with a black out chamber) or do i take .075 off the fl sizing die and have the chamber cut short to match. This would give me a full length neck and eliminate the long throat other than the reamer has all ready. I know I can use 360 Dan Wesson or 357 max brass but i have some extra new 357 mag brass and it is a lot cheaper and easier to get ahold of than the other options.