Any Luger experts here?

[afultz075]

My grandfather is lending me his Luger to see if I can figure out why it's having jamming issues. I have a hunch that it might be an ammo issue. Anyway, I figured while it's in my possession I might as well see if I can find out anything about it. There are surprising few markings on the gun. The metal on the gun is in pretty good shape and it's mechanically sound. The bluing shows it's age and has many spots where it's started to turn a brownish shade as seems to be common on older guns. The bore is pitted but the rifling still looks OK. I know nothing about these guns but I do know that he paid $600 for it 2-3 years ago.



^Front strap reads "1GD6"

^ "49403" is stamped under the barrel, "11335" is stamped about 1/4" above it

^ "03" is stamped in the area that's whited out by the flash