Purchased a 1920 Navy Luger 6 inch . sold as 9mm .9mm luger ammunition is too long and won't seat in chamber . .380 seats and loads from the clip? is a .380 the same dia as a 9mm kurz and it compatible to use

You better check the bore first and don't try to fire .380 in it. It is more than likely chambered for the 7.65mm Luger cartridge aka .30 Luger.

Not all Lugers were created equal, and caliber can be one of the differences. I tend to agree with CZU above.
Post some pictures - I am certain we can help lend more information.
And..... welcome to the forum. It's a great place to learn. The collective knowledge here is somewhat amazing.

The diameter of the brass base is the same for 9mm, 30 luger and .380 and all fit/feed from luger magazines. The bullet diameter of the 9mm and 380 are same. The 30 luger bullet is significantly smaller. Be sure of the proper caliber! If pistol was made right after WW1, it is most likely 30 caliber (.309).

Look around on the gun and see if you find Germany marked on it if so it was one of the lugers made up from parts after ww1 was over and built for export and could easly be a 30 luger.

Yes, it could be 30 Luger but more likely it is 9mm Luger. Many older Luger handguns will only accept ball ammo with the bullet seated fairly deep.

Of course this is all just guessing on our part. Do Not fire that gun with any ammo until you are perfectly sure for which cartridge it's chambered for. Take it to a competent gunsmith and have it gone over and find out what it's chambered for.

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SWCA #3437

That is not true. Any Luger will take 9mm Luger up to maximum cartridge OAL. It is just the contrary that may be a problem in reliability.

It most likely it's chambered for .30 Luger.

And do not try to fire .380 in it. It will chamber allright. But if it fires you may injure yourself and wreck the gun.

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Expect the unexpected

Agree with the above about it being in 7.65 or .30 Luger. This case from the base to the start of the shoulder is 17.6 mm, which means a .380 (edit - 9 X 17 mm) will likely chamber. Putting a .355" bullet down a .308" bore, however, not recommended...

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Alan
SWCA LM 2023, SWHF 220

Measure the diameter of the hole at the muzzle. If it appears close to .30, it is chambered for the 7.65 Luger cartridge, which can be thought of as a necked-down 9mm Luger. Except that the 7.65 Luger came before the 9mm Luger.

Having owned at one time or another five 9mm Lugers, I never had any difficulty in using any 9mm cartridge in any of them.

As to the one unanswered question, yes, .380 ACP is the same as a 9mm kurz and it compatible to use in place of 9mm Kurz. It's also known as: .380 Auto, 9mm Browning, 9mm Corto, 9mm Short, 9×17mm and 9 mm Browning Court.

It is not compatible with or the same as 9mm Luger or 9x19 parabellum.

It is certainly not the same or compatible with 30 Luger, also known as: 7.65×21mm Parabellum, 7.65 Parabellum and 7.65mm Luger.

If your gun says 9mm Kurz you're probably good with .380 ACO but with any vintage gun it only makes sense to have it checked to be sure as parts may have been changed or barrels rechambered. The consequences of being wrong are too great to risk it.

Look on the bottom of the barrel, right up near the chamber. If you see stamped numbers like 8,82 you have a 9mm Parabellum AKA 9x19 AKA 9mm Luger. Those numbers were stamped when the gun was inspected and gauged and indicate the bore diameter in mm. I forget if it is for the lands or grooves. If it has those numbers and they start with a 7 you would be very well advised not to fire anything other than a 7.65 Luger (.30 Luger) round ! And don't try a .30 Mauser or 7.62 x 25 Tokarev round either.

If you are comfortable disassembling the gun look down the bore with a flashlight and see if the chamber necks down. The .30 Luger cartridge is necked.

9mm & 30 luger.jpg

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All of the above - a simple check

take a pencil, normal one to the muzzle - a 30 Luger (7.65mm) will be tight, a 9mm will slide down easy - just an easy first check....

Post photos. I'm not satisfied that you have a genuine Naval Luger, and you seem very inexperienced with those arms. No one who isn't familiar with Lugers should buy one without considerable research. I hope you haven't been swindled.

For starters, I don't recall a Naval Luger in 7.65mm.

Who told you this is a Navy gun? Not all six-inch barrelled Lugers are Navy guns.

Does it have a grip safety? Model 1908/14 Naval Lugers do not, as they were easier to make during wartime, and the grip safety is awkward and is disliked by many. Frankly, I'd prefer an 08/14 as a real world Luger, but collectors may vary.

The German Navy first adopted the Luger design in 1904. The Army version followed in 1908. Both have some variants.

We need GOOD, sharp photos, and include one of the rear sight. Is it adjustable?

If you have almost any Luger in good condition, it's an expensive gun. Some are REALLY valuable. Learn fast what you have and what it should shoot.

Caliber .30 Lugers were used by Switzerland, Portugal, and Finland, maybe by other nations. We have members here from all of those countries. See what ammo they have there. And we have at least one man here, a retired FBI agent, who has a .30 Luger. He can tell you what ammo he uses. I've read that the .30 cartridge feeds especially well, due to the bottlenecked case, like that on the .357 SIG.

Caliber 7.65mm Lugers made after WWI usually had barrels a tad under four inches, as the Treaty of Versailles forbade Germany making longer barrels and forbade 9mm guns, save for internal Army and police use. And I think their guns maybe all had to be reworked WWI examples. Not sure.

After Hitler became Chancellor, regulations were disregarded, and 9mm's and longer barrels reappeared.

I have a .30 as well. When I bought it I ordered some Sellier & Bellot ammo for it as it was the easiest to find at the time.It shoots well and have never had a feed or ejection issue. Now if I need more ammo I have to have someone order it for me . Stupid NY safe act prevents gun owners from ordering online and having it shipped to them.

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To the OP. Does your pistol look like this?

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BCCI Life Member #2068

"....Purchased a 1920 Navy Luger 6 inch ...."


So it's a Post WW1 Weimar rework ('1920' marking) most likely and many were made up into 30Luger as well as 9mm for export.
Most all of these are made up of parts, refinished, and with replacement bbls of all sorts of different lengths on them when they were destined for export.
Any Luger with a bbl longer than the Standard Army pistol and with the rear sight still back on the rear toggle,,, it got to be called a 'Navy' pistol,,didn't matter if it was ever a Navy issue weapon or not.
Stick adjustable rear sight out on that longer bbl,,,and it became an Artillery model on the market.
They imported and sold Lugers with bbls up to 12" long and probably more in the post WW1 yrs. All sorts of configurations and in both 30 and 9mm cals.

Make sure the bore is clear and no obstruction in front of the chamber keeping the round from seating all the way.

Simply look at the end of the muzzle.
It's either a .30 cal (7.65Luger) or a .35cal (9mm Luger)

If you are unsure of the caliber, take it to someone that can ID it for you. Learn how to take down the pistol and clean and maintain it.
They are not hard to do and it's part of the charm of owning them.

Have fun with it and be safe.

as said above, lots and lots of lugers have received a 6 inch barrel - both back in the 20's, 30's, 50's on up, and to this day, I have had 6 inch barrels put on receivers in 7.65mm and 9mm - 6 inch is a great length for fun shooting.
I don't know of any real navy in 7.65mm but as said, its a common term

Ed