I have not seen any on the shelves including at my Bnechrest guys shop. Load length? Same as the old ones. Load 'em as long as the magazine will let you. I'd try a heavy charge of Varget for my goals. Data will be straight across the board with a standard SMK. The BC is a bit better but I would not say it's earth shattering. I'd like to hear your results. on this one at 600.
The best firearm for self defense? Any loaded one will do.