While a very expensive custom built bolt action rifle will be more accurate than a semi-auto, I think most of the people who dismiss the semi-auto as less accurate are simply wrong.
Build up a $1500-$2000 AR15 or AR10 and build up a $1500-$2000 Remington 700 and I honestly believe that BOTH rifles are capable of being "1 hole" guns with accuracy differences that are so minute that neither has an accuracy advantage.
One semi-auto AR10 maker has rifles shooting 300 Win Mag at 4" at 1000 Yards.
I have personally built, and I currently own, Sub-1/2 MOA AR15s that shoot far better than I am capable of holding. One of my guns was borrowed by an Appleseed instructor, who, while holding it in a standing position with a sling, fired a 5 shot group of 3/4" at 200 yards using cheap WOLF ammo! At 100 yard ranges I've shot 1 hole groups with that gun off a simple plastic rest. And at 200 yards I've shot 1/2 MOA groups . . . and I am
not considered to be a good shot amongst the members of my shooting group.
Please explain how a bolt action gun that shoots 1 hole groups is better, more accurate, etc than a semi-auto that shoots 1 hole groups?
10 shot group:
And I am not talking about fancy uber-priced "F-Class" guns that weigh as much as your ex-wife and cost as much as your divorce lawyer. I am talking about guns that are available using off the shelf components that may be tweaked a bit for accuracy but don't require a second mortgage to own.