I agree the 165 Seirra's wouldn't be my first choice for moose either. Whilemoose aren't usually considered warriors whens it comes to dropping them they do have extremely thick hides & large bone/muscle massto consider. If you want to stick with Federal Premiums I'd suggest starting with 1 of the following :160 gr Nosler Partitions, 160 Barnes TSX or 160 TBBC. Another you may try is 160 Nosler Accubond which worked in my 7mm rem mag last fall on both my moose & elk harvests.

If I had to suggest just one to start it would be a Nosler Partition. Why??? It is a proven game taker, premium bullet that provides both energy release(wound channel)plusstays intact enough to pentrate deep (bones and tough tissues)and most rifles seem to throw them reasonably well, IME.

Congrats, enjoy and best of luck on your swamp donkey hunt!!!