No need for a large rifle to kill a moose something in the 7mm Rem Mag, 30-06, 300 WSM/Win Mag range will be plenty. You can of course use something big but it really doesn't gain you any killing power. If you want something a bit different the 7X64, 8x57 or 9.3x62 would work great too.
I have used the 30-06, 308 Norma and 35 Whelen over the years on moose with no complaints at all.
