The two symbols together on the case on the right and the two on the left stand for Defense Industries Organization (DIO) which is the government branch which manages all munitions production. There are two different forms of this same name. on these three cases. The case 2nd from the right has the symbol of the Islamic Republic of Iran which is also in the center of their flag, along with the two symbols for the DIO.
The tables below will allow you to translate the actual symbols and numbers on the headstamp. The top table gives you everything for Farsi (language in Iran) the other tables provide Arabic and also Hindi numbers.
Remember Farsi and Arabic are read from left to right, but the numbers are read right to left.
The dates are from 621AD so you need to add "21" to each of the two digit numbers to get the western date.