1916 Erfurt luger p08 unit markings
 

The only thing that confuses me about this unit marking would there really have been 600 and some guns issued to a single unit

It isn't necessarily the number of guns. It is a property mark and it could include pistols, rifles, swords, etc., in the inventory.
Ron

Thank you

So you do believe that it is a machine gun unit marking

Ron, that's a good point and one I hadn't considered. The OP's Luger is, I believe, the first three digit property number I've seen. It's certainly the highest number I've seen.

As unit marks were stamped at unit level, it would be interesting to see an inventory list. Would they have kept a numerically running list of mixed items or a list separated by type; e.g., Lugers, Revolvers, Swords etc.