Sportsman 20GA year of manufacture help

[Virginian]

Unless I am reading something wrong, your serial number is before the last produced number in 1942.
No date code on the barrel is not that unusual for any Remington shotgun up through the 1980s so that doesn't say much to me, but unless it had a Cutts or a PolyChoke installed at the factory, no choke marking is unusual. Researcher will probably be along and nail things down for you.

[Virginian]

Duh. I just realized you substituted an 'X' for the last digit. I was thinking the X was an actual part of the serial number like with some later Remingtons.