Haven't seen that particularly, but given the condition of your coin I would not be surprised if it was post mint damage (PMD). Or you could possibly have and error. My avatar shows a Wheat penny from the 50's that was struck through grease, rendering the last digit in the date completely absent. Also, on yours the rim to the left of LIBERTY looks fatter than the other side along with weak details in the motto and the IB in LIBERTY, so maybe even a weak strike of sorts. Just a few likely possibilities.