There are a lot of variables, but, in my opinion, a scope-sighted, properly regulated and sighted, big-bore double rifle, in the hands of a man who shoots it a lot, and shoots it well, is at least a 300 yard rifle.
This is not conjecture on my part. In Zimbabwe, three years ago, I took my Sable at 208 yards with my self-built double in calibre .450 #2 NE. Had he been at 300 yards, I am confident that the rifle was fully capable.
Three weeks ago, in Texas, I took a Scimitar-Horned Oryx at 154 yards, with my self-built double in calibre 9.3 x 74 Rimmed. Had he been further out there, the same applies.
The key is careful and accurate regulation, and sight-in at a good distance, NOT 50 yards.
