RE: 7mm mag or 300 mag
i was set on saying the 300 first till u said 300yds in my knowledge the 7mm would be the best for that kinda shot due to its a smaller and faster cartridge. 7mm would take smaller bears elk and deer but not cleanely on a moose unless u used real heavy bullets and had close vital shots and u wear extremely sure of your rifles accuracy. but im biting my tongue in saying this but id go for 300 win mag. 1shot