What size buckshot would you shoot? Would you be shooting lead or a tungsten-based product? I've never hunted deer with any type of buckshot, only rifles both fixed cartridge and muzzle loaders and shotguns with slugs. A lot of varmint hunters are using turkey chokes with lead buckshot with great success and many are also shooting the "Dead Coyote" through those same chokes, even though it seems pretty tight to me for such large "hard" shot.
Last year I shot some 2.75" 00 Buck that was issued to me over 25 years ago, through a pretty tight turkey choke, just to see how it would pattern. I was very surprised to see that it consistently put 8 of 9 pellets in 10" at 40 yards.
We only shot those rounds through riot guns with cylinder bore barrels and at very short ranges back then. It was devastating at those ranges but we'd never have thought about a choke any tighter or that the pattern would hold together at 40 yards.
There are probably many folks on here with experience in using buckshot for deer that can be of help to you. Just thought I'd share my experience with the 00.
"If he's out of range, it just means that he has another day and so do you."