Breech Plug for 12 gauge shotgun shell barrel

[Wudsruner]

I am planning a new "scrap yard" muzzleloader, and I am going to buy a Numrich 12 gauge barrel blank and use it for the barrel. I plan on using this because I do not have to worry about it blowing up (as black iron pipe barrels can) and leaving me fingerless. I have created a simple percussion lock and have the stock planned, and my only issue is how I am going to close the breech and make the barrel blank into a muzzleloader barrel. Can I use a bolt from the hardware store that fits and weld it in? I have no problem with exposed welds or anything cosmetic, it will be a beater/junkyard muzzleloader and the more "Mad Max" style it looks the better thank you all, and do not hold back on the criticism as I am a very beginner gun maker (if you can call it that ) and I am open to it always. If this is a horrible idea, please say so!

 

[Scota@4570]

It is not a horrible idea, making a ML shot gun. As you described it, it is extremely dangerous. Put the welder and common bolt away, they are not a valid solution. Get a copy of Brockway's book on recreating the ML double barrel shotgun. Study the part about how to breech a modern barrel as a ML. Do it that way, and stay alive.

If you are going to the trouble to make a shotgun, do a good job with quality parts and materials. Forget about the mad max zip gun idea.

 

[Pete G]

Why not order a muzzle loading barrel to start with

 

[Wudsruner]

Why not order a muzzle loading barrel to start with

The only barrels I've seen are around $150 and if I have a gunsmith install a breech plug on a $30 barrel I have $100 max into the gun because I will make everything else myself

 

[Larry (Omaha)]

Can I use a bolt from the hardware store?

Wudsruner,
RH McCrory's book "the Modern Kentucky Rifle" says you can. I have made 4 breech plugs this way.

Flintlocklar

 

[bud in pa]

i have a 12 ga. damascus barrel I bought for $3. I looked up the dimensions for a 12 ga. breech plug. I bought a bolt of the same diameter and thread pitch. The barrel is 30 inches long after trimming the chamber end. I have a flint lock I bought from S&S some years ago,and a hunk of black walnut that has been drying for about 40 years. The barrel mics out to a full choke, which will make a good turkey or squirrel gun.

 

[ord sgt]

i have a 12 ga. damascus barrel I bought for $3. I looked up the dimensions for a 12 ga. breech plug. I bought a bolt of the same diameter and thread pitch. The barrel is 30 inches long after trimming the chamber end. I have a flint lock I bought from S&S some years ago,and a hunk of black walnut that has been drying for about 40 years. The barrel mics out to a full choke, which will make a good turkey or squirrel gun.

I would be very leery about using a Damascus barrel. If there is any rust in the welded seams of the barrel, there is the potential for one of those spots to split open under pressure from a powder charge. This could cause injury to you or someone close by.
Have the barrel checked by a reputable gunsmith before using. The life you save may just be your own.

 

[Col. Batguano]

A threaded plug with a minimum of 8+ engaged threads is standard for plugs and vessels that are under high pressure. The bigger the hole, the coarser / deeper the thread. A welded plug won't have that amount of bearing surface for safety, to say nothing of the softening the metal will undergo during the heating.

You might get away with your "device" as you are contemplating, but then again, you might not, and MAY make yourself a candidate for a future Darwin Award. Does the phrase; "hold my beer and watch this" sound familiar?

 

[Wudsruner]

A threaded plug with a minimum of 8+ engaged threads is standard for plugs and vessels that are under high pressure. The bigger the hole, the coarser / deeper the thread. A welded plug won't have that amount of bearing surface for safety, to say nothing of the softening the metal will undergo during the heating.

You might get away with your "device" as you are contemplating, but then again, you might not, and MAY make yourself a candidate for a future Darwin Award. Does the phrase; "hold my beer and watch this" sound familiar?

Problem is solved, I have bought a tap and a breech plug and I am going to properly install it into the shotgun barrel breech soon. After much contemplation and some funny but extremely helpful responses, I'm not going to act like a Kenyan poacher in his hut making guns that walk the like between elephant killer and pipe bomb!

 

[SDSmlf]

Appears you have two threads going on the same topic (4130/4140 Chromoly pipe for a muzzleloader barrel?). As I stated in the other thread. you will also need a bottoming tap to complete that thread in the barrel to properly seat your breech plug.

 

[Rifleman1776]

I would be very leery about using a Damascus barrel. If there is any rust in the welded seams of the barrel, there is the potential for one of those spots to split open under pressure from a powder charge. This could cause injury to you or someone close by.
Have the barrel checked by a reputable gunsmith before using. The life you save may just be your own.

Older Damascus barrels are frequently repurposed into fine ml rifles and shotguns. There is a well known ml gun builder in Missouri that specializes in doing this. His guns are drool worthy beauts and shoot fine. But, he knows what he is doing and undoubtedly avoids barrels that might be unsafe.

 

[Col. Batguano]

Breeching is probably the single most important process to get right in a build from a safety perspective.