Syd, certainly the 338 win is a great caliber and one many see as perfectly suited in particular for larger game such as elk or moose. However many of each species fall to the one you have in the closet now, all that is required is a premium bullet and driving it home!
Not to desuede you from buying a 338 or whatever but I ceratinly wouldn't let it stop you from hunting elk if you go with some other to spend your savings on either!