Strange 7.92 mm mauser headstamp

In fact at least strange to me, but as I know very little on this caliber it say not very much. Can’t find a thing of it. Headstamp " N 3 " on 12 and 6 o’clock. No primer crimp or seal, brass primer. Bullet factory crimped nickel plated jacked, little magnetic (magnetic core?). Who made and when.
Thanks, Jan.

It is Norwegian. There is also an "N l " headstamp. I forget if it was made at Raufoss or Norma, but it is for Norway. Perhaps Morten or one of the others Scandinavian collectors can fill in the holes.

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Thanks for the info John and pbutler. Wishes, Jan