What is the difference between a 9 mm and a 9 mm Markov round?

Answer 1

There are about a dozen cartridges that have 9mm as part of their name. If you mean the 9mm Parabellum (sometimes called 9mm Luger) it is longer than the Makarov, not as fat, and has more power. The 9mm Makarov is actually 9.27 mm.

Answer 2

9mm can refer to a number of rounds, including the 9x17 Kurz/Short (also known as .380 ACP), the 9x18 Makarov, the 9x19 Parabellum/Luger, the 9x21 IMI, etc, etc. Assuming you're talking about a 9x19 Parabellum round vs. the 9x18 Makarov, there are some substantial ones. Aside from having a shorter case, the Makarov has a round that actually measures 9.3mm, so the projectile won't fit through a 9x19 barrel. The Makarov was designed to get as much power as possible out of an unlocked breech pistol; all the 9mm cartridges listed above, except for the 9x17, are for locked breech pistols.