I have always taught, and continue to teach, that if you can't hit an eight inch circle consistently at the distance to the target, you're not qualified to hunt at that distance. I still believe that hitting the eight inch target consistently is the best single individual test of a hunter's shooting ability for hunting large game. That distance depends, obviously, on what shooting stance you choose. Your level of accuracy shooting off-hand limits your off-hand range; your ability shooting from a bipod may increase your distance:accuracy ratio. Both have to be considered when deciding whether to take the shot.
Based on his blog, I think Richard Mann would agree with that.