your model 310 was made between 1972-1975.
If it's not on the breech or barrel then it's a good chance there is none. For a time back in the 40's that Benjamin did not put any serial numbers on air guns. I also own one that has no serial number.
Most likely around late 1956 according to Crosman who owns Benjamin.
The value of a Howard Miller clock model 660-310 can vary based on its condition, age, and market demand, but typically ranges from $150 to $400. The serial number may help identify its production date and authenticity, potentially impacting its value. For a precise appraisal, consider consulting a reputable antique clock dealer or checking recent sales of similar models.
The Benjamin model 310 is part of a series of rifles that included: 310 BB rifle 317 .177 pellet rifle 322 .22 pellet rifle All were made from 1940 to 1969 Today Crosman owns Benjamin and Sheridan air gun's, see the link below for a partial list of Dates of Manufacture. Scroll down on the list until you find the 310 section. It may help if you have the serial number.
The Benjamin model 312 was part of the 310 series of rifles that included 310, 312, and 317. They came in .177 and .22 caliber. Production started with the model 310 in 1940 and ended with the model 317 in 1969, the 312 fell somewhere in the middle of that time period
The Benjamin 310 series (310, 312, 317) were made between 1940-1969. My best guess it was made sometime during the 1950's they did not start putting on serial numbers until around 1957 so that should help narrow it down
This model 310 was made in 1957
310 is a composite number.
The reverse of adding 310 is subtracting 310. If you start with a number and add 310, you can return to the original number by subtracting 310 from the result. This operation effectively undoes the initial addition.
310 is 4% of 7,750.
36 = 729 and 310 = 5904936 = 729 and 310 = 5904936 = 729 and 310 = 5904936 = 729 and 310 = 59049
The factors of 310 are 1, 2, 5, 10, 31, 62, 155 and 310.