This is the rifle they sell, the caliber caught my attention ....
This is a Mauser M71, made in 11,15x60R.
Made by Mauser Oberndorf, Erfurt Arsenal, Spandau Arsenal, Danzig Arsenal and Amberg Arsenal, Birmingham!, some were made (and stamped) by Steyr also.
Yours probably...
Your rifle is not the original military rifle, but a sporter, converted by a gunsmith.
Because it has no iron sights, be sure it was not converted to a shotgun!
The cartridge is a lead bullet, black powder number.
Moulds are made by RCBS, Lyman and some others, 340 - 370 gr, .446 dia.
Dies are available from RCBS, Redding, Lee and so on.
Cases are hard to come by and even harder to make from other cases.
Bertram is a source....
HWL