I have an 1853 with the same star on the back and it air test at 12- 28 but it will come in at 12- 27 and 12- 29 sometimes. I also have an 1865 which is the size of a dime which has the roman numeral 3 III on the back which is 3 times bigger than the one shown in the picture posted above but that one the 1865 I have comes in at 11- 12 - 04-05