This is a rather strange coin. The portrait and crown is that of the Sassanian king Bahram I, who reigned as shahanshah from 271 until 274 AD. A previous owner of the coin, Robert W. Schaaf, has commented that the inscription if total gibberish! There is also no known coin of Bahram which has a double circular inscription as displayed on requester Chuck's silver coin.
The only match is a known fake dinar (see this image from Tom Mallon). See the side-by-side comparison below. The known gold fake, however, is also a *perfect* match to Chuck's coin. On the reverse the gouge on the right side, stretching from the lower right of the fire altar through the waist of the right attendant, is present in exactly the same manner on both coins. However, the color of Chuck's coin is not gold, as would be expected. We can conclude that the same counterfeiter also produced silvery specimens to pass off as drachms. Interestingly, the flan looks cast while the image itself is struck unto the coin. This is the only explanation I see for the double strike on the obverse on Chuck's coin, an error not present on the coin in the linked image.
In the image below, the gold coin is the known fake dinar and the silver coin is requester Chuck's coin.