Need help type of caliber friends gun

[mikelets456]

My friend just inherited a gun and it states 9 m/m (380). Is it 9mm or 380?

I’ll post a picture when I get home. It’s a 1911 Llama

[jthrelf]

Not positive, but sounds like .380ACP which is also known as 9mm Kurz (short) or 9x17. Whereas 9mm Luger or Parabellum is 9x19. 9mm Kurz is the more European name of what us Americans call the .380 Automatic Colt Pistol.

[Grizzlytrap]

could be wrong, but a 380 is a shorter 9mm. Kinda like a .22cb is shorter then .22lr

[raxar]

could be wrong, but a 380 is a shorter 9mm. Kinda like a .22cb is shorter then .22lr

Yes and no, they use the same diameter bullet but the .380 case is slightly smaller in diameter.

[Delkal]

Yes and no, they use the same diameter bullet but the .380 case is slightly smaller in diameter.

Correct. A .380 has a smaller rim. When I am reloading every now and then a .380 case gets mixed up with the 9 mm and it usually pops out of the shellholder or jams something up. I don't think any of the .380 cases made it to the end (which is good).

FYI there is another 9mm out there that some people mix up. The 9x18 Makarov. It uses a slightly larger diameter bullet (.365 vs .355) but the rim is the same as a standard 9mm. All you have to do to make 9x18 brass from a 9mm case is to size it and trim it 1mm. Performance wise the 9x18 is slightly hotter than the .380.

So summing it up what most of us just call a "9mm" is officially a 9mm Parabellum or a 9x19 (metric designation). But for some reason it is called a 9mm Luger in the US. And don't forget the 9mm Nato that is loaded to a higher pressure. Consider it a 9mm+p so don't shoot it in and older pistol. Clear?

The 9x18 Makarov is 1mm shorter with a larger diameter bullet, and the .380 is a 9x17 with a smaller diameter case.

[bortle]

When he see's the price of 380 ammo he'll wish it was 9mm luger

[SevenMilePete]

Yes and no, they use the same diameter bullet but the .380 case is slightly smaller in diameter.

Interesting. I just looked it up, and .380 ACP bullet diameter is actually 9.00 mm. not .380. .380 in = 9.652 mm.

[Bang]

Similar to a .38 S&W Special being .357", just shy of 36 caliber. The company stretched the truth a little to appear more powerful and gain a sales advantage.
9mm bullets are .355" and .356". .380s are usually 95 grains or thereabouts. 9mm usually are not below 115gr.

A .380 case is almost straight-walled, the neck being .001" smaller in diameter than the base. The 9mm Luger (aka parabellum) is quite tapered, with a neck to base difference of .011". Many don't realize the taper is there. Reloading (resizing) removes the taper and is one of the reasons gun makers state firing reloads in their product is a no-no.

[Zeke2A]

Not positive, but sounds like .380ACP which is also known as 9mm Kurz (short) or 9x17. Whereas 9mm Luger or Parabellum is 9x19. 9mm Kurz is the more European name of what us Americans call the .380 Automatic Colt Pistol.

What he said .....excellent description. Technically you can fire a .380 cartridge out of a 9mm chambered firearm ( more than likely will not cycle) you cannot do the reverse without damaging the firearm.

[Pizza Bob]

What he said .....excellent description. Technically you can fire a .380 cartridge out of a 9mm chambered firearm ( more than likely will not cycle) you cannot do the reverse without damaging the firearm.

Well, yes and no. Theoretically, rimless cases headspace on the case mouth against a shoulder in the chamber. In reality they generally headspace off the extractor. However, with the .380 Auto having a slightly smaller rim diameter, headspacing off the extractor may be problematic in a gun chambered for 9 mm x 19. Guess that's where the "Technically" and "Theoretically" come into the equation.

Adios,

Pizza Bob