The pictureshows a view of this Old Tin Colt 8 Cork Pistol Toy Gun. This is not a cap gun. A cork fits into the end. There is a spring action lever (on the side not pictured) that is pulled back and released when the trigger is pulled. It is marked as follows:
COLT - 8 MADE IN JAPAN
It is not dated but believed to be from the 1950s. The gun measures about 6'' long. It is in near mint condition as pictured with only light wear on the silver finish of the trigger.