It's called statistics and probability.
10 rounds is usually considered a high enough sample size to determine exactly where your gun is likely to place the bullet at any given time on demand (accuracy) and also give you a very good idea as to how tight a group the rifle, ammo and shooter can repeatedly achieve (precision). This is what shooters (and hunters) who are serious about precision and accuracy try to do as it gives them a very good idea as to how far they can do an ethical shot on big game.
Not quite the same as rapidly shooting out the truck I know.
I realize this is going to be like barking at the moon but since you asked.
For more and better info I would recommend Hornady podcast "Your groups are too small"
It may be accepted if you're shooting a match, but it certainly doesn't indicate where a rifle will place shots under hunting conditions, especially big game rifles. Fine for gophers though.
The only shots that count when you're hunting game bigger than bunnies are the first, second, if needed and maybe a third shot, which usually means you missed the first two. All of this from a "COLD BARREL"
Hunting rifles, for the most part, are not heat treated or designed to shoot that many rounds in a string.
When shooting a barrel that has been sighted for ten shot strings, which shots do you use to dial in your zero?
I run into people regularly, shooting "ladders" watching their bullets walk all over the target as their barrels head up, and adjusting their scopes to the point of impact their rifles harmonics have finally settled down to, at much higher temperatures than they will ever shoot a Deer at.
Any good hunting rifle should have its zero set for the first shot from a cold, fouled barrel. The second shot will be very close, and a third if needed, will be close enough as well. After the third shot, many rifles start opening up the groups they will shoot.
I have one rifle, with a very expensive after market barrel, which has been specially heat treated, after purchase, before being installed, to shoot acceptable groups of ten rounds. It cost a lot of money and time to get that barrel.
I won't say there aren't "unicorns" out there capable of shooting good groups under such conditions, there are, but they're jewels, and few and far between.