You know…if they’re looking to add a light machine gun to the game the M249 Saw came out in 1989. So it would be an 80s weapon for an 80’s based game. Would be awesome! A hundred round clip, and they could call it the Z249 Zaw. You know for copyright reasons.
KSP 58 (FN MAG) would be more appropriate. Not really a light mg, but it’s considered a “middle class” mg. Very popular still to this day- and also very beautiful.
It would be the KSP90 which is the swedish adaptation of the FN minimi. The M249 is the american adaptation of the same gun. Looking at the amount deployed at that time it would be about as common as the Barret .50
Be warned though, this one would chew through your supply of 5.56 ammo in a very short time
On a more serious note, I’m missing some more “historicly correct” civilian guns. As an example the .243 and .270 was about as common as hens teeth in 80’s Sweden. The countryside was littered with rifles in 6,5x55, 30-06 and 9,3×57 though, mostly husqvarnas and repurposed military rifles.
Also as far as shotguns go, up until early in the 80’s anyone that owned land over a certain area (a few acres) could apply for a shotgun permit and many did so, so the country was (and to some extent still is) swamped with cheap side by sides. Mostly husqvarnas and cheap Belgians. These are still refered to as “torparbössor”. A torp being a small homestead or cottage.
The one military rifle that I feel is missing and that would still have been issued in large numbers to the local guardsmen at that time is the old swedish mauser. Other than that, most of what I saw during my military sevice in the mid to late 90’s is pretty well represented except for the KSP58 that nygren mentioned and the Pansarskott m/86 (The AT4 disposable anti tank weapon to the rest of the world)