Back in 1966 I conducted an experiment using a 3x9 scope on a .308 rifle. Sand bags, solid bench calm day.
I shot three 1" groups at 9 power and then just for the fun of it, shot three groups at 3 power. The lower power groups were 1 1/4". Since that time I have carried only 1.5 to 4.5 scopes on my woods rifles. 3x9 or 4x12 on my plains rifles, although I still carry a fixed 6 on my .264 mag antelope gun.
Try the 3x9 test. You may be amazed at how little difference the extra power makes.
williek