Colorado, John and Dan - good to see you here. Just got back from a 10 day rendezvous - best in Canada by far, imho, of course.
: I took the 14 bore rifle, (Bitch) and never failed at the 200 and 300 yard gongs (which, of course, weren't part of the competition - oh well). Trouble is, I had trouble with most all of the close range targets, but finally found out what was going on with a 50 yard paper buffalo offhand target. My 4 shot 2 1/2" group was fairly good, except for the 3rd shot which I uncerimoniously, flinchingly dumped into his right front foot. Because my ball lacked the tremendous hydrostatic shock of a .300 Weatherby Magnum, my paper target didn't die instantly from the hoof hit, so I won nothing in that event, a 38/50 deserves hardly a mention - for 4 shots, not bad but for 5???.
: I hadn't thought of this angle before, but Dan is spot-on regarding the phony black powders in respect of the regulation of the rifle. Ball obturation, rate excelleration in the bore and effects on the recoil curve profiles are all mixed in the equation of regulation. Trial and error are just part and parcel of finding what is required - with each powder, each patch, each alloy and each lube - containing thousnads of combination possibilities.
: One must remember or merely keep in your mind that a buffalo lives mostly in the lower third of his body, somewhat like a goat. Shot placement is paramount in quick kills. Small diameter bullets seemingly have little 'visible' effect on him. They are tough. My experience is very limited, but I do have some second hand experience through friends who hunt buffalo every year. Keith's .75 works well, as did a .60 Hawken Taylor make for o'l Sam C. The .375's and .416's work as do .458's in modern stuff. I think if using a modern gun in .375 to .458, I'd try to break the beast down, not try for the lungs as is the custom on edible game.
: To say a 12 bore isn't up to the task, perhaps one merely needs to follow Baker's note on feeding that beast.
: I would think an underfed big bore might be less effective than a properly fed medium bore rifle. I am thinking that a 140gr. charge in a .62 might be much more effective than a 90 gr. charge in a .72. Compared to a 12, the 20 bore is indeed a medium or even small bore. When fed correctly, the 12's and larger are truely impressive. Paper ballistics just don't deliver justice - at least not with the formulae currently being used.