For ranged weapons, best quality weapons never jam but miss on any roll that would result in a jam. Good craftsmenship gives the weapon reliable. Reliable weapons only jam on a natural 100. It doesn't say anything about rolls that would result in a jam, missing instead. Is this intended?
RAW it seems there would be very little reason to upgrade a weapon from good to best. Added to this the lasgun already gains nothing from going from common to good. Perhaps rethinking the benefits of ranged weapon craftsmenship may be in order.