It might work at 20 yards -- they'll even fire over sandbags at 20 yards -- but 20 yards is hardly a realistic engagement range, and it allows an approaching enemy to easily pick off defending AI. With the saddle/setDamage 1 trick, you can get the AI to fire at a realistic range (200 meters+). I have no idea how BIS could have possibly coded it like this, but so far, this is the only thing I've found that works.