.001 inches. Makes a difference depending on what you are shooting, how old the barrel is, etc..
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.
5.62 is bigger
Noop. an M16 fires a 5.56mm (or .223 caliber) bullet. A .45 caliber shoots a bullet that is ~11.43mm.
@ 3 miles
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.
Conversion kits are available from Ceiner and auction sites for Colt or military surplus.
Need to know rate of twist and what you are going to use it for.
Varies from the 40's to the 70's
5.56 The cartridge used in a M-16 is a 5.56mm caliber Nato round It is also referred to as .223 caliber Remington. The actual bullet is small, weighing between 46 to 52 grains and having a true diameter of .224 inches. Bullet and case are 5.4 cm long
The .22 Long Rifle is a rimfire, whereas the .223 Remington is a centerfire cartridge. The .223 uses a longer 'spitzer' projectile vs. the rounded projectile of the .22 LR. The .223 tends to be a heavier projectile, and has a much higher velocity than the .22 LR.
In terms of power, or diameter? A .22 has a bullet diameter of .223 inches, the same as the .223 Remington and 5.56 military cartridge. The .222 Remington actually has a bullet diameter of .224 inches.
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.