Not a good idea. Shooting 9X19 in a 9X21 chamber puts a lot of extra pressure on the extractor causing it to fail prematurely.
9mm MKV is not the same as 9mm Luger.
380 and 9mm projectiles are .355 in diameter _________________________ Most of the time, when people use the term 9mm, they are referring to a 9mm parabellum. A 9mm parabellum cannot be fired from a .380. The 9mm cartridge is longer. _________________________ The BULLET is the part of the cartridge that is the projectile. While 9mm parabellum and .380 ACP use the same diameter bullets, the CARTRIDGES are not interchangeable.
no
No. There are more than a dozen DIFFERENT "9mm" cartridges, and they do not interchange. The most common is 9mm Parabellum- also known as 9mm Luger or 9x19. It does NOT interchange with 9mm Kurz, 9mm Corto, 9mm Makarov, 9mm Ultra, etc.
There are SEVERAL 9mm cartridges- the most common is probably the 9mm Parabellum (9mm Luger). A 9mm Parabellum BULLET (not cartridge) is typically slightly smaller than a .38 Special bullet- .356 instead of .357. The 9mm is frequently (not always) lighter- and shorter. Other 9mm cartridges (such as the 9mm Makarov) will have different bullets.
Yes. 9mm Luger is the 9x19 cartridge, also known as the 9mm Parabellum, and that's what the 9mm Sigma is chambered for.
No. Most 9mm pistols are fitted for 9x19 rounds, but a few use 9x21mm. or 9x17, or 9x18, or 9x20
No.
The factors of 921 are: 1, 3, 307, 921
921 = 92100%
Sometimes
Assuming you're referring to the 9x19mm (also known as the 9mm Parabellum or 9mm Luger) and the .380 ACP (also known as the 9x17mm, 9mm Short, and 9mm Kurz), the answer is no on both counts, and it would be extremely dangerous to try this.