Scrapgun
This weapon's design is... less than ideal. Cheap, certainly, but less than ideal. Add 1 UNRELIABILITY point.
Spring guns are blowback battle rifles manufactured en-masse with the cheapest materials and methods possible, generally to arm vast levies or guerillas. Most of them are chambered in 7.62x39mm, a readily available intermediate cartridge, since the action is unlikely to handle anything above that. They are the epitome of scrap-metal firearms design and can reliably kill a man at a distance of no more than 200 meters, if the action doesn't blow up in the user's face. A spring gun's iron sights are more of a decoration.