Contact marlin customer service through their website.
The first 2 numbers are the year of manufacture- 1971. Nice rifles.
aa27056
The Wikipedia site for marlin 336 rifles includes a table showing how to use the serial number to find date of manufacture.
This can be accomplished by providing the serial number to your Marlin model 1895 lever action 45-70 chambered rifle.
With the serial number that you provided,your Marlin rifle was produced in the year 1979.
Your serial number indictes that your Marlin rifle was made by them in the year 1985.
With the serial number that you have provided,your Marlin rifle was made in the year 1996.
Your serial number indicates that your Marlin rifle was made in the year 1971.
Your Marlin rifle was made in the year 1987,with the serial number provided.
1890
19031818
Your serial number indicates that your Marlin model 336 was made in the year 1971.