Lots of guys here, in years gone by, thought their #3 Enfields were the best moose ctg. going. Some will admit their new '06's or even .7mm mags are better, others not so sure (especially about the 7mm).
The '06 and 180 CL's or 220RN RP's were favoured for many years. Others went to Win. PP's and Imperial/Dominion KKSP's.

The old 215gr. KKSP RN seemed to work just about as well, they say, from the .303.

My first moose rifle was a .458 2"(American). It was satisfactory for the job. Pull the trigger, shoulder the rifle, walk up to the moose, set the rifle aside, take off the jacket and get to work.