Barnes bullets have literally re-written the books on bullet weights and high velocity cartridges. By that I mean you can now take advantage of the ridiculously flat trajectories associated w/ low for caliber bullets weights w/o the fear of insufficient penetration.

I shoot Barnes TSX bullets, both tipped and not, from .300 and .270 mags regularly. My favorite deer load from either, regardless of species, is the 110 gr TTSX from the .270.

I'd suggest you get 2 boxes of the 130 gr TTSX .300 Wea Mag, have him sight in 2.25" high @ 100 yds, which should put him ~ +3" @ 200 yds, dead on @ 300 yds, and -4" @ 360 yds, should he be confident out that far. These are also the lowest recoiling .300 Wea Mag loads you can purchase OTC, too.

Always looking for small bore Francotte SxS shotguns.