When I was growing up(about 100 years ago...) the maximum, effective, humane, 'kill shot' was to be taken at no more than 300 yds. Of course, now, with better gear, that has been changed considerably, to nearly 400 yds. My point is that if a 'humane' attempted shot is seen to have a max range of 400 yds, why wouldn't this apply to either a 16" or 18" bbl? The ballistics would be a non factor... Just sayin...