OK, let me say right here and now that I have a new-found respect for the .577 Snider. Comparable to the .45-70 is all that I need to know as that is a round I have an old soft spot for, along with my Ruger #1 that is its mate.
There's a lesson here. Not being familiar with the snider I looked it up in Barnes' book. His comment that it is "not very practical for American hunting" steered me to relegate this round to the "plinker" category.
Although I have a lot of respect for Mr Barnes, I nonetheless should not base an opinion on his, or any other's, opinion. Empirical evidence of my own should be the cardinal rule. I can't speak about something I've no experience whatsoever with.
Many Thanks for the post and the link, Pete. That's a beautiful gun and a beautiful animal. Amen.