Locarion would determine the outcome. In a close quarters battle the grizzly would massacre both of them. Out in the open, my money is on the lion. The gorilla, while massively strong, it is not in the same class as either of the others.
They will look right at you so just pop them between the eyes or through the top/center of the skull. No fuss and little blood. As others have said....a trash can full of water works too but can also net you an animal cruelty charge if a Karen/Ken sees you doing it
Varget has been my "go to" powder for these spicier loads. The Viht powders did NOT like being compressed. Power Pro seemed to plateau far below where I was trying to get. Ram Tac did not get anywhere close to my sought velocity.
It should certsinly meet your requirements. I suggest using hard primers, my experiments have shown that softer ones, such as federal, do not handle the pressure very well
I have been playing with the 308 Nas3 casings and while they work, I still prefer Alpha SRPs and my modified 277 fury brass. The nas3 work fine if you do not mind NOT being able to reload them. For me that is a non-starter. Some of my alpha brass have 15 firings on them (all well above max).
I made a bunch in my younger years but never had a power hammer.....had to use a wide variety of sledges from 16oz mini's to 8# full size with shortened handles.
I had mine ,which was on an Origin Long action with a proof barrel, throated specifically for the 212 ELD-M. I shkuld have kept it.....thing was a danged laser