What would be the date of manufacture on a Marlin 60 (purchased in 2014) with an MM serial number ... ie: MM123456J?

1964

https://www.gunvaluesboard.com/marlin-serial-numbers-dates-of-manufacture-1664.html

https://www.google.com/search?q=Marlin+Limited+Edition+model+6081Year+of+manufacture

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On Marlin-branded Model 60 rifles, the first two digits of the serial number indicate the year of manufacture. For example, if the serial number starts with 18... The 18 is significant, for subtracting it from 2000 gives the date of manufacture for the rifle, 1982. Likewise, a serial number starting with 17 would be a rifle manufactured in 1983.

This method has not been uniformly followed. It is valid only from 1971 through 1999. Prior to 1971, the first two digits indicated the year of manufacture. For example, a rifle with a serial number starting with 70... would have been made in 1970. Starting in 2000, this same old method has returned; the first two digits once more indicate the year of manufacture directly, with no subtraction required.

Hi Gary,here's a link to the Marlins gun book, Blue Book of Gun Values MARLIN FIREARMS COMPANY Rifles Centerfire Lever...

this is copied from a site, the web address is pasted below.

The serial number depending on the model of rifle, will be located either on the upper or lower stock tang, or side of the receiver.
http://www.gunvaluesboard.com/marlin-serial-numbers-dates-of-manufacture-1664.html

also if you find serial # you may find more info here.
http://oldguns.net/sn_php/marlinlookup.php

From 1962 thru 1968 Marlins rimfire rifles (other than the 39 series lever actions) used a two letter date code that was stamped on the barrel. This date code is different than the one already listed, as Marlin rimfire rifles (other than the model 39 series) did not have a serial numbers until required to by Law after 1968. The first letter of the date code represented the month of manufacture while the second letter indicated the year. This date code was usually stamped on the left side of the barrel just in front of the receiver.

TRY THIS LINK
http://www.gunvaluesboard.com/marlin-serial-numbers-dates-of-manufacture-1664.html

http://www.gunvaluesboard.com/marlin-serial-numbers-dates-of-manufacture-1664.html