Is there a way to determine caliber from the headstamp of war production Axis ammunition? The headstamp includes the maker code, year, St+(coated steel case) and lot or batch number. It appears to be 9mm parabellum, but just wanted to know for future research.
First of all, welcome to the forum.
On German militarily production the caliber was not on the case.
As you mentioned correctly, the code of the factory who made the case.
The material S* (brass) or steel (mat code, St or St+), Lot number and year.
Very broad question! Some, but not all, Italian 9x19mm ammunition for the Berretta M38 machine pistol from WWII is marked “9M38” on the headstamp. Other calibers do not as best I can recall. Some Japanese ammunition like the 7.7mm rimmed has the caliber, but most other calibers do not. Again, this is just my impression. others can give you a much more detail answer.
Generally, I think you will find that very little military ammunition has the caliber marked on the headstamp, from WWI or WWII or since. The average soldier sees very few different calibers he has to worry about, and better be able to identify these without having to look at the headstamp. There are some exceptions, but they are relativelhy rare.
Thank you to Lew and Dutch. I know determining war production ammo can be difficult. I understand that sometimes even eroneous information was stamped on ammo and guns to keep the allies from figuring out where productions facilities were and dropping a multitude of large, irritating bombs on the plants. Just makes it that much more fun to dig around though. You meet interesting people and make some good contacts. Have a Merry Christmas.
Fake or erroneous information on ammunition is actually pretty rare, and usually only done to disguise the national origin of a country. Most often this is done to hide supply to one or more sides in a civil conflict, or to a country covered by an international embargo. Coded ammo is much more common. It is not done to give erroneous info, but to hide the number and/or location of ammunition factories.