I just bought some ammo for my Repeater, and as it wasn't expensive I bought all three different variants. As far as I can tell, the high velocity rounds give better range. But the Express ammunition seems to be simply a better version of the regular ammunition. It also doesn't seem to be that much more expensive.
Does Express ammunition have any drawbacks I missed? Or is it simply a superior version of regular ammunition, and there is no need to use regular ammo at all?