30 cal luger ?
 

My friend has what I belive to be a 1920 commercial Luger in 30 cal luger.
Now here is the problem , it has no markings other than DWM on the toggle,made in Germany on the right side of the frame near the barrel ,and gesichert near the safety.
The barrel dose not look like itt is big enough for a 9mm so I think it is a 30 luger.
I got him a box of Winchester super X that are bottle necked and need o make sure they are the right ones.
A round will feed but I'm still worried about case failure.
If any has one or knows how to tell for sure "safely" pleas let me know. Thank you.

A quick means of checking to see if the bore is .30 caliber is to take a loaded cartridge from your box of Super-X .30 Luger loads and insert the bullet into the muzzle. If the bullet is stopped from entering all the way by the lands, it's a .30 caliber bore. If it's a 9mm, the .30 caliber bullet AND neck of the cartridge will go in until stopped by the shoulder of the case.