Cheimison, there was an Unreal (1) mod out a long time ago called Serpentine. You'd have loved that, it had the most realistic bullet and gun physics I've ever seen in a game, including new ones. You actually had to lead a moving target to hit it, and it also allowed you to aim down the sight. It changed all the weapons to real guns and was a lot of fun, but unfortunately ended up being pretty obscure. If you still have Unreal lying around, you should check it out
here. To put the time-frame in perspective, this mod pre-dates Counter-Strike.