If you mean 9mm Parabellum (also called 9mm Luger)- no. the 9x18 (Makarov) is fatter and shorter than 9mm Parabellum. It is not a true 9 mm.
No- two different cartridges. They are for different guns and do not interchange. The 9x19 is also the 9mm Parabellum or 9mm Luger- the 9x18 is the 9mm Makarov.
NO. The .380 ACP is a 9 x 17 cartridge. The 9x18, also known as the 9mm Makarov, is not truly a 9mm cartridge- it is 9.27mm. The cartridge is too long, too fat, and too powerful to be shot in a .380 ACP pistol.
No. Not all 9mm cartridges are the same. 9x19 (a.k.a., 9mm Luger, 9mm Parabellum), for example, is different, hence, not compatible with other 9mm cartridges, such as the 9x17 (a.k.a., .380 ACP), 9x18 Makarov, 9x21, 9x23 Mauser, etc.
No. .380 ACP is 9x17. The 9x18 is the Makarov- not only a longer cartridge case, but the bullet is larger (the term 9mm is used loosely) Unlike revolver cartridges that headspace off the rim, these headspace off the mouth of the cartridge case. Do not try it.
No. There are several different calibers that are called 9mm. These calibers are not interchangeable. A quick rundown of 9mm pistol cartridges: 9x17 also called 9mm Kurz, 9mm Short or .380 Auto 9x18 Makarov, also called 9mm Makarov 9x19 also called 9mm Luger, 9mm, 9mm Para, 9mm Parabellum 9x21 also called 9mm IMI 9x23 also called 9mm Long, 9mm Largo
No. Most 9mm pistols are fitted for 9x19 rounds, but a few use 9x21mm. or 9x17, or 9x18, or 9x20
do not attempt to fire!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
NO- outside of case dimensions, the 9x18 uses a .366 bullet designed for the Makarov. The standard international cartridge, 9mm Luger (9x19) uses a .355 bullet. The Luger will not fit in the Makarov, and if you try to fire the Makarov in a standard 9mm gun, you may just damage the gun or blow out the barrel
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.
The .380 ACP is a type of 9mm... 9x17, and is sometime referred to as the 9mm Short or 9mm Kurz. It is NOT the same as the 9mm Luger/Parabellum (9x19), and it is NOT compatible with any other type of 9mm cartridge (such as the 9x19 Luger/Parabellum, 9x18 Makarov, 9x21, 9x23, 9x25, etc.).
9mm Largo and 9mm Parabellum are different guns. No.