[magnum1954]

I have a Marlin 336 in my office. Verified from Marlin that it was built in 1971. Trying to sell on Gunbroker and have had watchers say it could not have been built in 1971 because it is stainless. Ser # is 71 163xxx Pictures attached. Need some info on this rifle if there is any out there. Thanks!!

 

[straightshooter]

You might try checking that out with Marlin. Perhaps Marlin knows more than what armchair experts know. Not saying they are wrong but I would check with Marlin first before believing different than what Marlin says when the gun was made.
I found this while checking info about it. According to this your gun was made in 1971 because if the beginning numbers being 71.
From what I have seen there were two types of stainless model 336 rifles. One was called xlr models. I could not find what years they were made. There also was a 336ss which was a stainless model and it was first made on the year 2000. Perhaps your 336 is an xlr made in 71 as your serial number shows year being 1971. In 1973 the first two digits of serial number are subtracted from 100 to get he year made. IE: beginning serial of 22 would be a 1978 model.
http://www.marlinowners.com/forum/336/24934-model-designation-serial-numbers.html

 

[magnum1954]

I called Marlin and all they could do was verify the date of mfg as 1971. They indicated they had no other info on the rifle.