A .50 calibre cartridge is measured as 12.7mm in metric terms, while a 7.62 projectile is in the .30 calibre range.
metric vs inch measurement
As far as diameter, there is very little difference. A .357 is .358 in diameter and a 9mm is .356 in diameter.
Yes. .38 special is a revolver cartridge and .380 is an auto cartridge. Also, the .38 will almost always have a heavier bullet and more muzzle energy than a .380. The .38 bullet is 0.357 inches in diameter while the .380 is 0.355 inches in diameter. Technically, the .380 cartridge is considered part of the 9 mm class of bullets. [9 mm x 19 mm = 9 mm Luger or 9 mm Parabellum, 9 mm x 18 mm = 9 mm Tokarov, and 9 mm x 17 mm = .380 ACP]
Yes they is a differnent. When people say "38" they usually mean .38 special, which is a revolver cartridge. .380 ACP is a semi-automatic cartridge. The bullet in a .380 cartridge, even though it's called .380, is actually very slightly smaller in diameter, and lighter than the bullet in a .38 cartridge. The .38 bullet is 0.357 inches in diameter while the .380 is 0.350 inches in diameter. Technically, the .380 cartridge is considered part of the 9 mm class of bullets. [9 mm x 19 mm = 9 mm Luger or 9 mm Parabellum, 9 mm x 18 mm = 9 mm Tokarov, and 9 mm x 17 mm = .380 ACP]
It depends on the bullet weights. The 9 mm (AKA 9x19 mm, 9 mm Luger, or 9 mm Parabellum) is faster than the .380 ACP (AKA 9 mm Kurz) except when you compare the lightest .380 bullets to the heaviest 9 mm bullets. If you compare the same bullet weights in each, the 9 mm is always faster.
11.5 mm bullet diameter
The diameter of the bullet casing, measured at 7.3 mm, is 7.3 millimeters.
Millimeters, it is the size of the bullet.
7.62x39mm
Yes.
Size of the bullet
They are different ways of expressing the same thing. A bullet that is 7.65mm is just that- 7.65 millimeters in diameter. Is the US, we frequently use caliber rather than millimeters- that same bullet was be a .32 caliber- or 32/100ths of an inch in diameter.