Generally, a bullet's caliber has NOTHING to do with its accuracy.
So your question cannot be answered.
However, a 9mm is usually a handgun round, used at close range (0-15meters). A .223 is typically used at longer ranges, but could be used close-up as well.
At distances greater than 20 meters, up to 500 meters, the .223 will be more accurate, if the weapon is dialed-in.
Caliber refers to the diameter of a bullet (bullet is the part of a cartridge that is fired out of the gun). A .223 caliber bullet is .223 inches across. It is normally used as a rifle cartridge. a .45 caliber bullet is more than twice as wide as a .223, and is usually used in pistols. The .223 is lighter- it weighs about 1/4 of a .45 bullet, and they are different shapes- .223 is usually pointed, the .45 is rounded.
Noop. an M16 fires a 5.56mm (or .223 caliber) bullet. A .45 caliber shoots a bullet that is ~11.43mm.
@ 3 miles
.001 inches. Makes a difference depending on what you are shooting, how old the barrel is, etc..
1000m
It depends on what you mean. Strictly speaking, a .223 cartridge has a .22 caliber bullet, but when people say .22, they are usually referring to .22 Short, Long Rifle, or Magnum cartridge, which is different than .223.
No But the Caliber is the same but theres more powder in the 223
Conversion kits are available from Ceiner and auction sites for Colt or military surplus.
More accurate than 90 percent of the people who will shoot it.
Varies from the 40's to the 70's
Need to know rate of twist and what you are going to use it for.
The M16 is an assault rifle that is a .223 caliber / 5.56 mm. like any weapon it is only as accurate as its shooter, <><><> It can be very accurate.