Yes
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
m-16 fires .223
No, the two numbers are clearly different. In a more practical note, "7.62" is the diameter (in millimeters) of a bullet typically fired from a .30 caliber rifle such as a Chinese SKS or Russian AK-47 rifle, while "5.56" is the diameter (in millimeters) of a .223 caliber bullet like the M-16 or AR15 rifle.
No. They're not even remotely close to being the same. The two bullets are the same caliber but that is where the similarity ends. The M-16 bullet is about 3 times the length of a 22LR, completely different in shape, about 4 times the weight, etc. Also the cartridge used in the M-16 has more than 10 times the powder than a 22LR, giving much higher muzzle velocity.
The M-16 Carbine or M4 use a 5.56x45 Nato round or the civilian version .223 Remington
ww1 french mle m16 was 8mmx50mm lebel.
A little over 15,800 feet
Well, it depends on what you mean. The caliber is "determined" at time of production based on whatever caliber the manufacturer wants it to be. The caliber can be determined later by looking on the barrel. The caliber will almost always be stamped somewhere on the barrel.
No. Rifling is intended to stabilize the projectile.
About 6336 miles per hour (mph)
If you mean a 50 caliber gun, it takes a 50 caliber bullet, but there are a couple of different kinds. Are you referring to a rifle or a handgun? If you are talking about a handgun like a desert eagle then it is a 12.7x33 in metric, .50AE standard. If you are talking about a rifle then it can be 12.7x99 in metric, .50BMG standard used in rifles like the M-82 or it can be a 12.7x108 metric used in rifles like the Gepard M-1. Also the bore in all the .50's is really .511.