I haven't been able to log in here for about a week but since I can, I'll throw my $0.02 in
Not that I know anything about guns, scopes, or deer hunting but...... I'd stick with the 40mm scope. Better light gathering without the need for crazy high mounts. Also a variable is good to "zoom in" & get a better look at your target before you make the decision to squeeze. I'm not familiar with your hunting territory around home but at Chickenbuck there is really no need for anything more than a fixed 4 or so. OTOH if you head a few miles West around my stomping grounds, a person can shoot as far as he/she cares to.
My personal preference on my deer rifles. 3.5-10x40mm, but I do own a couple 3-9x40mm also.
Of course this all goes out the window if I'm carrying that little handgun that Dusty took a fancy to. I'll keep the iron sights on that & keep the shots under 80 yards or so.
Frost on the ground this morning is giving me the itch to get in the woods again!
