Never shot a moose and probably at 75 Y.O. never will.
However, sould fortune smile upon me, I know exactly what I would take for the hunt.
I would prefer to take my custom mauser in .35 Whelen as it spits the 225 gr. Barnes TSX out the muzzle at 2710 FPS and all the elk I've taken with it have been bang/flop/DRT. I'm positive that bullet will reach the vitals regardless of the point of impact and most likely pass on though the other side. If the OP's gun in a single shot he could use those bullets with their very sharp nose. Last elk killed was at 350 yards so a .35 caliber rifle does not necessarily mean short to moderate range only.
Second reason for the .35 caliber is moose country usually hasa few Grizzly Bears in attendance as well. Don't think I'd want to use a 7-30 Waters against an angry Yogi who just might want to appropriate your moose.