One thing I don't think anybody has mentioned. Bolt action rifles have less moving parts, which means when you shoot it, there is less chance of anything happening to the gun to throw it even the slightest bit off target.
The Semi autos had many moving parts, and these sort of things rattle and shake and move when a gun is firing which might effect the accuracy of said weapon.
But at the ranges that an open-sight rifle is going to be useful at (out to maybe 600 yards, usually quite a bit less than that if you want a first-shot hit), the semi-auto "shimmy" isn't going to affect anything.
Open-sights, I wouldn't bet on hitting a person at much over 400 yards, unless they're standing stock still in the open.
Semi-autos are also less punishing to shoot, since the action soaks up a surprisingly considerable amount of recoil.
RE: Garand vs all other WWII rifles - The Garand is only inferior in one area, IMO, and that's in its lack of being able to tactically reload. You can "top off" with stripper clips. Detachable magazines are definitely better for topping up. Reloading when empty, though, I'd say the en bloc clip is about as fast as dropping/inserting a WWII-era mag.
Where the Garand shines: The sights are 10x better than the German or Soviet rifles. Disagree all you want, but go out and shoot a notch/blade or notch/post sighted rifle, then pick up a Garand, M1 Carbine or AR15 with the tried and true diopter sight on it, and see how much easier it is. The sight radius is also considerably longer.
Why the former Soviet Union and it's (former) allies have stuck with putting pistol sights on their rifles so long is beyond me.
@ Stiletto: I think German engineers could over-do their work on anything. "Oooh, look, it's 80% of perfection, we'll just work it over a LOT." And it turns out worse. On that note:
@angelangel: I work on cars for a living. BMW and Volkswagen have nothing but an un-earned reputation. They break more than other brands, excepting stuff like Volvos (the newer ones, anyway) and Mercedes-Benz. Nothing can out-break a MBZ. Why they break so much is simple: the engineers take something that SHOULD be simple, say a power window system, and instead of putting a couple of switches with a motor and a current-detecting torque cut-off, they wire it up to the CAN with a full-on electronic control module for EACH WINDOW.