Re: TBAC 30P-1 on a 300 blackout ?
A short 30P-1/30BA is a special order custom item. We can make it as short as you want as long as it's an integral number of baffle lengths. It's only for people who have a special need for a shorter length and are willing to put up with less suppression performance. I can't tell you how much louder it will be.
For the cartridges you listed, the regular one is the best choice.
I would only recommend getting a special order short version if I already the full versions for everything, really need a shorter version for a special application, didn't need maximum suppression, and was definitely going to put a lot of rounds through it for the special use. Otherwise the regular full size versions are the way to go.
hope this helps,
Zak