Bukkit

I found on some servers with guns that when I aim, I see in the first person that I am aiming. This is because of the server resource pack, the item replaces with else item that looks like an aiming gun. Is it possible to do something like that using CrackShot?

The way they did that was actually, and unfortunately, by retexturing "pumpkin". And therefore, unless you know enough of how to implement the pumpkin to appear on someone's head after activating zoom module. No.