I used to always scope em. Now about half of my 13 barrels are not scoped. I scope barrels that are meant for long range (223 etc.). My deer hunting barrels are each way. I have a 375 scoped and a 30-30 and 45-70 unscoped. Have a 41 mag each with a scope and without a scope. If I hunt along a field edge and plan to take a long shot I take the scoped gun. If hunting in a treestand with a 50 yard shot potential I take the unscoped ones.
I used to never be able to shoot open sights accurately, but I have really worked on it over the last year and half and now prefer open sights for shot at deer 75 yards or less. I shot a deer last year with the open sighted 45-70 (my first one with open sights). So I guess it depends on the situation but if you are shooting good with open sights at the distances you will hunt at, you may not want a scope.