• Friends, our 2nd Amendment rights are always under attack and the NRA has been a constant for decades in helping fight that fight.

    We have partnered with the NRA to offer you a discount on membership and Muzzleloading Forum gets a small percentage too of each membership, so you are supporting both the NRA and us.

    Use this link to sign up please; https://membership.nra.org/recruiters/join/XR045103

Modern shotgun barrel conversion

Muzzleloading Forum

Help Support Muzzleloading Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Kentuckyjed

.45, .50, .62 cal.
Joined
Aug 15, 2022
Messages
534
Reaction score
617
Location
Kentucky
Wondering if anyone has built a smoothbore out of a modern shotgun barrel 12 or 20 gauge? Don't know how the modern steel and wall thickness would work. Just curious because I'm sure someone has tried it. Input please.
 
The suggested way in Brockway's book was to make a long breech plug that threaded the chamber and had a snout that fit the forcing cone. The long plug had a powder chamber.
 
I've seen an old break action shotgun converted with a big bolt threaded down the barrel, with a flash hole and spot for 209 primer drilled into it. It's definitely doable.
 
Wondering if anyone has built a smoothbore out of a modern shotgun barrel 12 or 20 gauge? Don't know how the modern steel and wall thickness would work. Just curious because I'm sure someone has tried it. Input please.
An old NEF or H&R Parder single shot barrel would be perfect for your project and easily bought on Gunbroker for 100 bucks or so.

Cut off the under lug that houses the shell ejector and get busy building.

I'm sure a machine shop could soften the transition from fat breech to thin barrel.

Post up the pictures when you begin the build.
 
I've fired BP loads out of a single shot, so the problem certainly isn't the barrel.
But after reading the comments I'm curious to see how you do the breach and adapt it to a stock.
Nifty project.

You thread it and make a plug to fit. If it's chambered for cartridge, cut about half the chamber end off, thread it in as deep as a tap will go, then make a cone-seal plug with pre-chamber like a patent breech because it will be long. Weld on a tang or file/machine a hook for a standing breech that you can buy a casting for and fit to the stock. Drill your flash hole through barrel into plug, line if if you want to or don't. Grind off all the hangy stuff on the bottom of the barrel and solder on tenons to pin it to the ML stock. If you don't have a lathe you could probably do it with an alloy bolt (grade 8), drills, taps, and files, though you will never get a perfect seal between the barrel's forcing cone and your homemade breech plug. You could install it with high temperature, permanent threadlocker and probably be just fine with a hand-filed fit.
 
I’ve seen an adapter for them to that just pops in the back and then is loaded like a regular muzzleloader. And I myself have thought about dabbling in it.

20 gauge to 209 Muzzle Loading Adapter

Not sure if that what you are looking for or just a full on modified barrel.

Anthony

Stay away from that adapter, it is extremely dangerous! H&R made a muzzleoader from their single barrel break open shotgun back in the 70s. There were 2 versions, one had a threaded breech plug and the other had a press in plug retained by an O ring. It's possible for the adapter to blow out if the breech is opened after a hangfire and the gun goes off. Allegedly a shooter was killed not long after they put the gun on the market when that happened. The breech plug caught him in the head. It would have been 45 or so years ago and I can't find any documentation currently though it was widely reported at the time and H&R stopped production of that variation and it was the only gun we ever banned from our shoot.
 
Stay away from that adapter, it is extremely dangerous! H&R made a muzzleoader from their single barrel break open shotgun back in the 70s. There were 2 versions, one had a threaded breech plug and the other had a press in plug retained by an O ring. It's possible for the adapter to blow out if the breech is opened after a hangfire and the gun goes off. Allegedly a shooter was killed not long after they put the gun on the market when that happened. The breech plug caught him in the head. It would have been 45 or so years ago and I can't find any documentation currently though it was widely reported at the time and H&R stopped production of that variation and it was the only gun we ever banned from our shoot.
Thanks for the tip! I’ll stay away from that. I suppose one could just brass shell shot shells and load it that way with powder and such. But sort of defeats the whole idea of true “muzzleloading”. I’ve wanted to try what the OP has written about myself.
Maybe I’ll just get a dedicated muzzleloading shotgun.

Anthony
 
I used the brass off of plastic hulls to hold the "ignition source" ;)
I'm not sure adapters had come out yet.
Dave Canterbury has several videos on YT on the versatility of the single shot shotgun and field loading with black powder and minimal tools.
Non-traditional for sure, but interesting stuff nonetheless.
 
Early H&R muzzleloaders would fully open, the later ones, would only open far enough to put a cap on.. the O-ring breech plug
, of the later ones, would hit into the 'hump' of the frame if there was a delay.. I have two of them ( rifle and shotgun ) one of each version.

Respect Always
Metalshaper/Jonathan
 
I built this 20 gauge flintlock using a Stevens single shot barrel. I cut the chamber off and had a breech plug made and installed. The machinist told me that he could have bored the chamber out and soldered in a sleeve that would have given me another couple of inches barrel length. It was a handy canoe gun that I sold on the forum awhile back. I didn't like the way it handled due to the length and I don't have a canoe so I let it go.

IMG_4332.JPG
IMG_4333.JPG
 
Back
Top