ORIGINAL: english setter

Hearing that .45-70 BP buffalo guns throw 500 gr doorknobsin competition shoots @ 1000 -1500 yds. HOW??? BP sabots not even close and my .30-06 w scope can barely do that! I consistently hit chucks @ 500 yds and drop 150 gr spitzers in their laps @ 700 - 1000+ yds - 9x scope.
I recognize that .45-70 has big slug and powder charge retains lots momentum and may have efficient BC and has ultra accurate appature sight and calibrated elevation BUT front sight would cover the vitals of a SCHoolBUS! so how in hell could it out shoot a .30-06 and way farther than PRB or inlines??? thanks