there are some known counterfeit 1944 nickles that have no mint mark on them -all real 35 % silver coins will have a large mint mark upon the rear -- P, S , D
matter of fact thats how the counterfeiter was busted --due to NOT having the mint mark on the "fake 1944 nickels" -- his name was HENNING -- HE MADE ONES DATED -- 1939 , 1944, 1946 , 1947 , 1953 AND ONE UNKNOWN DATE AS WELL. (might be 1945* )-- its believed that over 100,000 of his bogus nickles got into the money supply -(there are some folks who collect these "fake nickels")