I have admittedly not even gotten to oil yet, and only used cheat mode+tech mode to check, but why is pistol ammo separate from Rifle ammo? Realism, yes, that makes sense, but given you can quickly get a rifle, and the pistol is worse in all ways, why bother?
I've seen a mod where Pistols had a damage bonus and/or extra range, but that isn't the case here either.
Also, why have Piercing pistol ammo?