50 bmg berdan primed brass


#1

I picked up some berdan primed 50 bmg brass. 50 at 12, R at 9, D at 3, and 56 at 6. I looked thru my books and couldn’t ID it. What is it?


#2

This was produced by Armeria F. A. San Cristobal, Dominican Republic.


#3

What is the meaning of dates 50 and 56?


#4

To what I know:
50 = caliber .50
56 = production year