Need help to identify this weapon!

[m3bobby]

Could be a spotting rifle or a sub caliber trainer for a much bigger gun.

[ThatFALGuy]

Could be a spotting rifle or a sub caliber trainer for a much bigger gun.

This was going to be my guess. By the fact it is stockless, has packaging that looks to be original to it, the configuration of the barrel, etc. I think that is exactly what it is. I had one years ago in .50 for use in the 105mm, though it used a special shorter cartridge, not the full length style we are accustomed to seeing.

edit to add:
Depending on what artillery it was made for, it could potentially be very valuable. Subcal devices aren't extremely rare, but they would have made nowhere near as many of them in comparison to however many they manufactured of the armament it was intended to be used with.

[guns ltd]

Could it be from an aircraft. Stuka???? The case looks like it may be for something else and was just picked up to store this in. just a guess.
John

[Bill Grist]

Luftwaffe proof marks as the type associated with Krieghoff, so I beleive it is some type of sub-caliber device in 8mm Mauser (7.92X57mm) for A Luftwaffe Aircraft cannon, or possibly a device to bore sight a aircraft cannon ...BILL

[guns ltd]

I knew you would come through for us Bill.
I was thinking Aircraft also.
have a good day.

John

[Marko H]

Looks Madsen m/40 machine gun parts or other model of Madsen.

Here is link: Madsen Light machine gun
Next "description of the Madsen model 1940" and there is several parts diagrams.

Another page Madsen 23mm aircraft cannon: Madsen Aircraft Cannon 1 Machine Gun V1 Repeating Weapons

Parts look similar to mee. Sorry my bad english....