Thanks for the tips. I'm kind of new at this. I did check that post out to see if someone already posted something that could help. There was one, but it was more of a CoD/military rocket launcher, not so much one Soldier uses.
I did look for some reference pics and I thought the Black Box would be the easiest to do (It helps I use it a lot in game as well). I have tried looking for tutorials on Google and other places, but the only TF2 weapons I could find tutorials for were Heavy's minigun and Scout's Force-a-Nature. (The latter of which is helpful since my bro's going as a Scout soon).
Anyway, something like this.