I assume you mean "0.3 ounces". Anyway, at 9 grams, it isn't close to the "correct" weight for an 8 reales should be around 27 grams. Even though it seems to be seriously clipped, it still seems too low. That, and the oddly-shaped lions, make me almost certain it's a reproduction of some sort.
Here are the main output mints for cob-style silver coins, together with the last date given in the catalogue:
- Mexico City (catalogued under Mexico), issued until 1734
- Lima (catalogued under Peru), issued until 1751
- Potosi (catalogued under Bolivia), issued until 1773; one known specimen has an "incorrect date" of 1778
Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis