I have a FN Supreme in 243 that I cannot pin down a "born-on" date. I've Googled ad infinitum and the best I can tell, it had to have been produced sometime between 1958 and 1973. It has the factory engraving, bolt and shroud "in the white", FN marked buttplate. The serial number is 4 digit preceded with a capital C. I procured it from a friend a number of years ago, since then it's been sitting in the safe. He said it had only been shot a few times, from the condition I believe that to be true. The Supremes did not come with rear sights, and many had receiver sights mounted. This one has been factory drilled and tapped, but has a rear peep sight that may even be factory. Does anyone have an idea how to pin down the date of manufacture? The proofs are all indicative of ranges of dates.

TX, nice rifle.I believe if you remove stock you will find 2 numbers which refer to the the year of manufacture.I recall them to be on right side of receiver in area below where receiver sight mounts.I could be mistaken though.Scott

here is an earlier FN. The date shows in the second photo.
your rifle does not have the "grapes" in the checkering border. It has a side safe. The 243 came in in 1955. So for sure it's > 1954. my best guess would place your rifle in the 1958-64 timeframe.

as beautiful as it is why worry about date ?

https://www.24hourcampfire.com/ubbthreads/ubbthreads.php/ubb/showflat/Number/11261603/Searchpage/1/Main/776344/Words/+mauser/Search/true/Re:_35_Whelen_AI_-_Belgian_FN_#Post11261603

I'd not worry about the exact date either. Your rifle is about as good as it ever got for factory sporters, at least after they stopped making the genuine Mauser sporters. As nice as it is, I'd hunt it, but gently.

Congrats on a fine snag. Barry Browning at Shooting Investments had a similar one for sale not long ago.