A 12 gauge with 3 inch mags willhit quite a bit harder than a 300 mag. Id say take your pick of any of the 3 and you would be well served. The 7mag is gonna have a slight advantage intrajectory. But they are all pretty close...1 isnt gonna do anything the other 2 wont. Im sure you could find exact recoil #'s at chuckhawks.com


52-54 pounds of recoil for a 3inch 12 gauge and about 24 pounds for a 300wsm. More than twice the kick.