Cool
This was very helpful. Not only does it help you actually make guns, but tells how they work and shoot. I just finished making a Colt .45. It's not as great as the one in this tutorial, but it's one of my actually good creations.
What I wish you would do is tell how the gun reloads. Like the Colt .45. Does it reload like a 9mm handgun? Or do you put the rounds through the slot that opens when the gun is out of ammo? Also, you should've explained more about how shotguns work, shoot, and reload. There's lots of shotguns, like the pump-action, automatic, sawn-off, and others not even in any categories.