Hello,
Excellent coin !
Billon, or .281 silver but that is a bit uncertain given the fast devaluation in that period.
It is not KM#301 (minted in Brno, would have been for Jarek

), but KM#303 minted in Graz.
Minted 1621 and 1622. Interestingly, the year 1622 is mentionned "fraglich" = doubtful in Herinek's catalog (no picture).
References KM#303 and Her#945-946
There is another reference for those coins, work by Dr Hahn in Vienna: Die österreichische Münzprägung unter Kaiser Ferdinand II. 1620-37, 1. Teil : Einführung und Katalog der Kippermünzen (money trend 3/2011, 226-232)
Trouble is that he gives a picture of the Graz coin for 1621 without portrait but arms on the coin, #12:
Hypothesis is that types 1621 and 1622 are different . Yours would be Her#946 for 1622 and KM#303 (Krause puts both dates under a single reference).
I'll validate as soon as you make the request. Lets put both dates on the same sheet and I'll try to find pics for the other year and then split the sheet.
I'll search farther. Do you mind if I submit your picture to Dr Hahn in Uni Wien ?
Regards,
André
Quand l'Histoire et la Géographie se croisent sur nos pièces de monnaie ...