Surely, max range of any calibre is more dependant on the nut behind the bolt than on the chambering ? I've proven in the past that the humble little .22 lr can be both reasonably accurate and carry enough energy to be deadly to small game at what many would consider to be ridiculous ranges. (NOT by shooting at live targets at those ranges)
I've also seen much larger calibre rifles used by people who, quite frankly, would have been just as accurate with a catapult and some pebbles.
Shoot off-hand with no rests and you're limiting effective range considerably. Shoot from a comfortable seat at a bench with the rifle correctly rested fore-and-aft and you can start to see that, in calm conditions, most of our kit is actually far better than the best of us.