www.gunsandammomag.com has ballistic tables with different manufacturers of ammunition.
Same round, different name
.380 1903
380
Yes. 9mm Kurz (or Cortos) is the European designation for .380 ACP. also called .380 Auto.
None, the projectile diameter is the same for both - .355. If you are asking about a complete round of ammunition, the 9mm case is 19mm long and the 380 case is 17 mm long. This cartridge is called the ".380 Auto" for use with an automatic pistol. However, the most common 9mm round is the "9mm Lugar". This cartridge has a heavier bullet and a longer case, thus a larger muzzle velocity and energy than the .380 Auto.
how far does 380 bullet travel
Yup.
.380 ACP means .380 Caliber, Automatic Colt Pistol. Often shortened to 380 auto. In other parts of the world, the 380 ACP is called a "9mm short" (or Kurtz, Corto other languages for "short."). So yes.
Let a gunsmith do it.
Yes you can. .380 auto.
Same thing. Yes.
380 ends with a zero, so it is already rounded to a ten, so it is 380.