A 30/30 in my mind is a 150 yard gun. For some folks that are really good shots, perhaps 200.

Countless deer have been shot within these ranges with a straight 4 power scope.

The power you set your scope on does not correlate to the range you can shoot. With my shotgun, I set my scope on 2 power (1.5-4.5x variable scope). The majority of my shots will be under 50 yards. If i see a deer at 100, I usually have plenty of time to turn the scope to 4.5.