S21 and Kotenok are both semi-auto, which could create a balancing issue if their damage is too high. Also, it would be a bit strange if they were noticably more powerful than the 7.62mm assault rifles, considering they use the same rounds.
As for the Algstudsare, it’s calibre is simply too small to justify a major buff to its power.
Have you ever seen a .270 round in real ? Maybe it’s calibre is “only” about 7 mm but the cartridge case is much longer than the one of .308/7,62x51… And ingame it’s right now more powerful than the 7,62 mm assault rifle ammo.
Aand we’re speaking of a game so a little bit of tweaking here and there is allowed imho