Distinguishing Between 9 mm and 7.65 mm Parabellum on the Fly
 

Gentlemen,

IMO the simplest method is to try an insert a round of .32 ACP ammunition into the muzzle of the Luger.

If the Luger has a 9x19 mm barrel the .32 ACP cartridge will slip into the barrel right up to the semi-rim on the cartridge casing.

If the Luger has a 7.65 mm barrel the .32 ACP cartridge will stop before the case mouth enters the bore.

Best,

Kyrie

good point, will add this to the stickie of about the same name!

I said, use a pencil, if it fits easily it is 9mm, if it sticks a bit its a 7.65mm - but pencils are not as common as they used to be :)

We have an article with photos in the FAQ document.

Why search out a .32acp round when you can use a simple pencil? If you're near ammo, why not drop a .30 Luger cartridge or 9mm Luger cartridge onto the muzzle and see if the bullet fits?

A) I was offering another alternative. If you don't like it feel free to not use it.

B) I haven't seen a pencil in decades.

C) I'd rather be handling a live round that cannot be chambered and fired in the firearm I've examining.

Just saying' :-)

I printed a metric and imperial scale on my business card :)

Helps to measure cartridges and muzzles at shows.

If the pistol turns out to be .30 Luger, wouldn't that be the case after all?

I'm not sure I understand the question. A round of .32 ACP (7.65 mm Browning) dropped into a .30 Luger (7.65 mm Parabellum) chamber would rattle around like a BB in a boxcar. The only dimension the two cartridges have in common is the bullet diameter of .309 (or .308 if one is buying US produced ammo).

You're right to question my question! You totally wrote .32 ACP...and I processed it as .30 Luger. Forgive the "Senior Moment" Please!

Not an issue, friend. I’m senior enough myself that if I want to chat with old friends I have to have to use an Ouija board :roflmao: