One caliber to rule them all

Why are AR-15s chambered in .223 Remington?

Because nobody has invented the .233. . . until now:

In its own defense, the county presented gunfire noise levels taken Friday by sheriff's deputies. Sheriff's Lt. Ron Hundley said deputies at the industrial building shot a 9mm pistol and a .233-caliber rifle, guns typically used in O'Gara training. Other deputies recorded noise levels at five locations ranging from a quarter-mile to about 2 miles away.

Now, take your puny 6.8 SPC and 6.5 Grendel and get the hell out!!

.233 RULEZ!!!!1!!

On the other hand, the quickest way to piss off the citizenry is to keep them in the dark about what goes on in their AO; especially shooty stuff.

Imagine waking up to automatic gunfire, artillery simulators, and tire squealing without any knowledge of what is going on?