I'd say that's on the light side, but it should get the job done. It's the "iffy" shots where a twig interferes or the deer jerks or moves that the extra "oomph" pays for itself. I use 84gr 3Fg in my .54, 90 gr 2Fg in my .50
Personally, if I had two loads that, from a rest, put five shots in 2" at 75 yards with 65 gr or five shots in 4" at 75 yards with 85 gr I'd use the latter for hunting. The kill zone of a deer is 10". Better a hole all the way through both lungs than a well centered hole only in one and stuck part way through the other.
I'd say my average in 33 deer harvested is between 30 and 40 yards. That includes muzzleloaders, shotgun slugs and centerfire rifle.