If you are talking about a .45 acp The bullet diameter of .451 equates to 11.5mm. If you are talking about a bullet used in rifle calibers (45-70) etc.then the bullet diameter of .457 equates to 11.7mm.
.355 bullet diameter
Both terms describe the diameter of the bullet in decimal parts of an inch. For example, a .357 bullet is 357 thousands of an inch in diameter and the .45 bullet is 45 hundredths of an inch in diameter. These labels of bullets are most common in the United States. Much of the world refers to bullet sizes in metric terms, i.e. 9mm means a bullet that is 9 millimeters in diameter.
.355
The .357 part of the name means that the bullet diameter .357 inches. I do not know what the "Magnum" means in the name.
It's the same. The caliber of a bullet is its diameter.
It is how thick a bullet is, measured through the thickest part of the bullet, from one side to the other.
A 22 caliber bullet is 22/100 inches in diameter. A 7.62 mm bullet is 30 caliber or 30/100 inches in diameter there is no such thing as a 7.62 caliber bullet
As far as diameter, there is very little difference. A .357 is .358 in diameter and a 9mm is .356 in diameter.
The bullet is 22/100ths of an inch in diameter.
Caliber is in reference to the diameter of the bullet. A .40 (which is what I have) is .40 inches in diameter. A .50 caliber is .50 inches in diameter (half an inch). So a caliber is the inches in diameter. Not including the 9mm which I cannot stand
A bullet with a diameter of approximately 9mm. Not all 9mm projectiles are exactly 9mm in diameter - the 9x19 Parabellum/Luger has a diameter of 9mm, while the 9x18 Makarov has a diameter of 9.27mm, the 9x23 Steyr has a diameter of 9.03mm, etc.