Luger ID .30 cal or 9mm

[Josafoot]

Originally Posted by ithacaartist

Either .30 Luger or 7.65 Parabellum. None of the others is an accurate name for this ammo.

We used to recommend the "pencil test" for caliber. A standard pencil will plunk right down to the bolt face when dropped into a 9 mm barrel. In a .30 Luger barrel, it will be snug or a no-go.

I tried a Pencil and it was tight but I could push it through. Not a plunk.

I also tried a .303 British round and that went most of the way but got stuck where the bullet is at its widest. To be fair, I was not going to push it any further.

[Josafoot]

Pics of caliper and muzzle (round is a dummy .303)

I am not sure I id the caliper correctly. I rotated it around the barrel holding the wheel to open the jaws more. It reads nearly precisely 7.62 (7.619)

Is this correct?

[Josafoot]

One more picture of the stamp. Flash brings out the dirt and rust. Any recommendations for cleaning up lugers without ruining their value?

[Josafoot]

Pic

[ithacaartist]

Originally Posted by Josafoot

I tried a Pencil and it was tight but I could push it through. Not a plunk.

Then it's .30 Luger.

Originally Posted by Josafoot

One more picture of the stamp. Flash brings out the dirt and rust. Any recommendations for cleaning up lugers without ruining their value?

Painstaking, gentle cleaning with well-oiled 4/0 steel wool. Change out the wool frequently because it picks up rust--which is abrasive--as you go. A toothbrush with fine bristles helps in the corners. Avoid anything water based or acidic.