Amateur gunsmithing can be very rewarding, and can be a fun way to test your making skills.
ALWAYS be safe. Follow proper gun safety (Always keep it pointed down range). Be careful when testing. Do so from a distance.
Take inspiration for homemade guns from here: https://homemadeguns.wordpress.com
Making your own guns also be very dangerous, as the people in the comments will likely tell you. Never fire a gun if you are uncertain of its safety. With that in mind, we can begin.
Step 1: Check the Laws
CHECK LOCAL LAWS! It is very important to know the laws in your state before attempting to make a firearm, as you could get in serious trouble. Always make sure your projects conform to law.
The BATF in the US regulates gunmaking, so you have to make sure you are not building a machine gun, short-barreled rifle, "sawed off 'shotgun'", or what they call an "any other weapon". Research these if you are making an unconventional firearm or anything with a barrel length of under 18" and overall length under 26".
The BATF website is here: https://www.atf.gov/questions-and-answers/firearms...
As far as state law, I live in Tennessee so no worries.
Step 2: Project 1: Simple Hardware Shotgun
12 gauge is the most commonly used shotgun shell around here, and building a 12 gauge shotgun is one of the best ways to begin gunsmithing. Imagine what the people at the duck club will think when you pull this out.
Here are the parts you'll need:
1. 3/4" galvanized or black steel pipe, schedule 40. At least 18" long unless you have a gunsmithing license.
2. 1" end cap
3. 1" steel nipple, 6" long. Try to find one with no weld seam on the inside.
4. 2x6 if you plan to make a stock yourself. I had one lying around. I won't go into how to make one, but this might be useful: https://www.instructables.com/id/Building-a-Custom...
6. Strap wrench (for a barrel handle, optional)
7. 3/4 inch pipe brackets/clips
When you've gathered the parts, check out my instructable here:
If you don't feel like reading the whole thing, here's an overview.
The 3/4 inch barrel holds the shell, and when you pull it back into the 1 inch nipple it hits the nail in the back, firing the round.
Step 3: .45/.410 Pistol
There are many different ways to build a pistol, but a .410 or .45 is a good place to start.
I've included pictures of confiscated improvised pistols from other countries as inspiration.
Basically, what you will need is the following:
-3/8 inch pipe
-a method of keeping the round in place
-a method of ejecting a spent cartridge
-a method of striking the primer
Beyond that, let your imagination go wild.
Step 4: Finish a Kit or Project Gun
Another way to continue your gunsmithing is to find a muzzleloader kit or buy a partially finished project from someone else.
I found a muzzleloader stock and barrel for only $30 at an estate sale, and the only part I had to make was the firing mechanism. I achieved this by spring loading a brass hammer attached to a dowel. The trigger seats into a hole in the dowel, and when it is pulled it releases the hammer to strike the cap.
Step 5: Testing
After you have built your masterpiece and have made sure it is legal, you can move on to testing. I tested my shotgun by using a really long string, and recommend you do the same. Always ensure that nobody is down range or close to your gun, as you are making sure it does not explode.
Finally, prepare yourself for the surge of happiness that accompanies the successful bang!
And happy hunting/overthrowing ISIS.