I've had this game for a while, can't get sucked in like 3 did. I might have missed where it tells you how to upgrade weapons or something, anyways how do I do it? And does anyone have a list of weapons or locations of unique weapons?
Yeah - if you've purchased a mod for a given weapon you can hit the left shoulder button when you have the weapon selected in your inventory. That will take you to the mod screen where you can apply them. If you don't have any mods for that weapon then
the mod screen won't show any.