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Single Shot Shotgun – Improvised Arms and Ammunition Part 9

Making a Shotgun from a Pipe

We made a slider shotgun in another article, now we will move on to a more complex design that will provide a more “gun-like” homemade pipe shotgun. This type of pipe gun takes considerable more time, but functions like an actual single shot shotgun (other than the method of loading a shell into it).

In a standard single shot shotgun the gun breaks at the receiver and the barrel tilts down, ejects the spent casing and allows you to slide a new shell in. Then close the gun, cock it and it’s ready to fire. In this pipe shotgun it may take a little longer to reload, but it shoulders and aims just like a shotgun, and so will easily take game.

In this pipe shotgun, you will simply unscrew the barrel from the receiver, slide it forward enough to extract the spent shell, and insert a new shell. Then slide the barrel back in the receiver and screw it back in, it is now ready to cock and fire. As with older style single shots this design did not provide a safety, if you choose to design a safety for yours that’s probably a good idea.

completed home made pipe shotgun
Figure 1: completed pipe shotgun

Sourcing the pipe

So let’s start from the beginning, rummage in the garage for pipe or take a trip to the hardware store. I went to Lowes and spent less than $14 for a ¾” black iron cap, a 1”x 6” black iron nipple, and a 30” long piece of ¾” black iron pipe (or you can get an 18” or 24” if you want, but I wanted a longer barrel to help keep a tighter group as the pipe is an open choke).

breech and barrel
Figure 2 pipe to make barrel and breech/breech cap

 

This first section will describe how to create a breech with a firing pin and a barrel, around this you will design your stock and trigger assembly, or fire control group, whichever you prefer to call it. The first step is to mark center in the inside of the cap and drill and tap a hole. If you don’t have a tap you can do the same thing with two nuts. I drilled a 5/16” hole and tapped the hole with a 3/8” -16 tap.

worm farming

Drill through a bolt length ways with 2 different size bits, first all the way through with a smaller one, then almost through with a slightly larger one. Put the nut all the way on the bolt (this is to clean the threads after you drill this next hole). The next hole is a firing pin retaining pin hole that you will drill in the side of the bolt between the threads. Use the smaller bit you drilled through the bolt with.

breech cap completed
Figure 3: breech cap with firing pin, the nut covers the firing pin retaining pin

 

breech cap bolt with firing pin retainer pin
Figure 4 close up of bolt with firing pin. Note retaining pin hole and retaining pin in lower right corner.

 

It’s important to have the bolt head inside the cap; this will act as a bolt face (no pun intended). To get the right headspace insert a spent shell into the barrel pipe and screw the cap on hand tight, turn the bolt in until it just touches the shell, then tighten the nut on the outside. Now when you load and fire the gun the bolt will be against the back of the shell.

inside breech cap
Figure 5: inside of breech cap

 

drilling firing pin through hole
Figure 6: drilling bolt for firing pin

 

making firing pin from allen wrench
Figure 7: making firing pin from Allen wrench

 

filing retainer pin notch in firing pin
Figure 8: filing notch in firing pin for retaining pin.

 

File a notch in the side of the firing pin that corresponds with the retaining pin hole in the side of the bolt. Make a retaining pin that has to be driven in tightly, grind a flat on the side of the retaining pin and line the two flats up. Now you have a floating firing pin like in an AK or AR or SKS. No pesky springs to worry about.

Now that you finished the breech cap let’s make a barrel.Now making a firing pin, simply use an old drill bit or similar tool steel (I used an Allen wrench) and make the end small enough to go through the pass through hole, but the rest just thin enough to go in the bolt but NOT pass through the through hole. Grind slow and quench often to keep the temper of the steel.

cut threads off 1x5 nipple for breech
Figure 9: threads cut off both ends of 1×6 nipple.

The ¾” pipe is for the barrel and is pretty much a barrel already, except you may have to grind a little of the weld inside the pipe if it’s too tight for the shell to fit. The 1” nipple has an important purpose; it reinforces the barrel at the chamber. Cut the threads off both ends of the 1×6” nipple and cut one end of threads off the ¾” pipe. You can make the barrel whatever length but make sure it’s at least 18” to comply with U.S. federal law.

Once you have the threads cut off the 1×6” nipple and off one end of the ¾” pipe, and you have your cap completed with the firing pin installed, the breech and barrel portion of your gun is completed. It will look like this picture, except you will have the firing pin installed, I forgot to take a picture with the pin installed, but you get the idea.

pipe shotgun barrel
Figure 10 barrel assembly next to stock.

After you have the barrel/breech assembly completed you need a stock. I repurposed an old SKS stock that I had lying around; you can do something similar or make a stock from scratch. For the sake of this project we will go with a modified SKS stock.

First I chiseled the barrel groove to accept the larger barrel. As you may know, the SKS stock will have a lot of it cut out for the receiver/magazine well portion of the firearm, this, along with the slot for the bayonet were filled in with some scrap hardwood I had lying around. Oak was used for the large section and a piece of teak was used for the bayonet slot, whatever you have is fine, don’t even fill it in if you don’t want to; I just did it to strengthen the stock.

fill in bayonet slot
Figure 11 filled in bayonet slot, cut the excess off

 

scribe block for filler block
Figure 12 scribing the filler block

 

rough cut filler block
Figure 13 filler block rough cut

 

chipped and ground out for barrel
Figure 14 chiseled for barrel

 

First select a piece of wood for filler and mark it. After marking it cut it out and glue it in, now allow the glue to dry so that you can mount the breech and barrel to the stock.

 

fitting the breech
Figure 15 cap fitted into notches

 

sideview breech
Figure 16 side view of breech and cap

 

fitting the breech
Figure 17 close up of breech strapped in on finished shotgun

 

After you have the stock all worked out you can mount the breech assembly and the front barrel strap. To mount the cap/breech in the stock make two notches to allow for the ridge on the cap, this also helps hold it in place, you will also make two small filler blocks that go on the small flats behind the cap, this will also help reinforce it and hold it in place.

The cap is not attached to the 1” breech pipe, you can strap the cap in if you choose to, but I left mine unattached so it is easy to get out and clean. The barrel slips through the breech pipe and screws into the cap, and the breech pipe is strapped in so it isn’t going anywhere.

I’m pretty sure it was a 26 gauge sheet metal that I used for the straps, it’s pretty thin but not so thin it is useless. I used a one inch wide strip on both the breech and the front barrel strap. Get it as tight as you can on the breech and tight, but just tight, on the front because the barrel has to slide in it. To mount the strap on the breech I drilled slots in the seam of the filler block and slid the strap into the slots. Then I used a piece of paracord and a stick and twisted the cord to clamp the strap tight, and then I drilled from the side and put a screw in each side.

Next attach the front strap, screw the barrel lightly into the cap and wrap the strap around the front of the stock and put a screw in the bottom. Remember to let the strap be tight, but not so tight that the barrel won’t turn and slide in it. Now you can begin working on the fire control group (trigger and hammer).

 

front barrel band
Figure 18 front barrel band

 

notice the breech strap screw on right side of picture
Figure 19 notice the breech strap screw on right side of picture

 

trace paper pattern onto steel with pencil
Figure 20 tracing the hammer pattern pattern

 

cutting out trigger
Figures 21 and 22: cutting out trigger

cutting out trigger

 

 

cutting a sharp angle
Figure 23 make a notch to cut sharp angle

 

roughed out trigger
Figure 24: roughed out trigger ready to grind and file

 

For this I dug some ¼” plate steel out of the scrap bucket, but first I had to design the trigger and hammer. If you use an SKS stock then this design will of course work for you. But if you used something else or made your own stock, (or if you don’t like my design), then this may or may not work. Cut them out of paper or cardboard first to see whether they will work or not. You can just kind of hold them on the stock and look at them to tell.

rough out the hammer
Figure 25: roughed out hammer

 

cut thumb grippy grooves
Figure 26: cutting thumb grips on hammer spur

 

cut the borders of the trigger notch
Figure 27: cutting notch in hammer for trigger

 

finished hammer and trigger
Figure 28: finished hammer and trigger

 

Now I’m sure that by now all of the engineers and professional gunsmiths are just having fits, and to that I say “meh” because this will work and it is fairly safe. Notice I say fairly safe, even a real gun isn’t 100% safe, they blow up on people.

I was at a gun range a couple of years ago, the guy three benches down had a popular name brand store bought .22 magnum bolt action rifle. He experienced a critical malfunction while he was firing it. He didn’t lose an eye but he was bleeding from the face and the receiver was missing a fairly large piece.
Now I’m sure that by now all of the engineers and professional gunsmiths are just having fits, and to that I say “meh” because this will work and it is fairly safe. Notice I say fairly safe, even a real gun isn’t 100% safe, they blow up on people.

But I’d have to say that with moderate use you won’t have to worry about anything with this design. Just inspect all parts when you clean it and make sure nothing is cracked or anything. Anyway, let’s install the trigger and hammer.

I didn’t do anything fancy, I just laid the hammer and trigger on the side of the stock and eyeballed them. Then I marked the pin hole and drilled all of the way through the stock with a bit that would be tight for the pin so the pressure would hold it in place.

I installed the hammer first, I used a couple of washers on either side of the hammer to hold it centered and for ease of use. Because I didn’t have any better springs I used a coil spring behind it with a pin mounted on the back of the hammer as a guide/retainer.

After I got the hammer in and ready to go I then followed the same process with the trigger. When the trigger was in place I had to remove it a few times and file on it to let it release easier and smoother.

All that was left to do then was make a trigger guard. The band material was too thin for that so I dug up a galvanize joist hanger and cut a piece out of that. First I made a pattern by making a trigger guard from a thin piece of metal, and then I used that pattern to make the real one.

I used a Birchwood Caseytm bluing kit from Waldo’s World o’ Chinese goods on all of the metal parts. But you can rattle can finish it any color or colors that suit you or in a pinch why even bother, it will still work with no finish on it.

trigger and hammer pin holes
Figure 29 trigger and hammer pin holes

 

hammer spring in place
Figure 30 hammer spring in place

 

polish the hammer with 200 400 then 600 grit paper
Figure 31 polish the hammer with 200 400 then 600 grit paper

 

hammer with spring guide pin
Figure 32 hammer with spring guide pin

Last shot

So there you have it, a serviceable 12 ga from an old stock, a couple pieces of pipe, and a few bits of scrap steel. Make no mistake, it’s time consuming, but if you have lots of time and either no money or no other access to a firearm this will do it, and if you’re more talented than me, yours will look even better.

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About Eric W. Eichenberger

Eric W. Eichenberger
Eric Eichenberger is an avid outdoorsman, skilled marksman, and former certified range officer and instructor with nearly 40 years experience handling and repairing firearms. A skilled craftsman with a strong love for working with his hands, Eric spent 20 years as a carpenter and custom woodworker in high end homes. As a gold and silversmith he has created hundreds of pieces of jewelry over the years using the lost wax casting method. The grandson of humble country folk, he was raised with the “do it yourself” mentality and so is accustomed to coming up with unique solutions to problems utilizing materials at hand.

One comment

  1. While I mostly disagree with Eric’s weapons articles this one is very good. Most of us won’t have an SKS stock hanging around or be able to precisely drill out the bolt for the firing pin but for those who can this is a worth while project. Most drill presses of the type preppers have are not precise enough to do good work but because accuracy can be compensated with the size of the pin, it should be fine. As to the stock you can actually take a 2×4 and cut it diagonally for an improvised stock that might work? Anyway I always give credit where credit is due and this build has merit and is much better than the normal slide shotguns offered to preppers. Those will still work in a pinch but this one is better and of course requires more work but nothing to complicated or time consuming. In this case the extra work is worth it.

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