12-gauge powder charge, sub-caliber bullet single shot

[WilliamDahl]

OK, try not to laugh too much, but I have this strange idea that I would like to try with an old single shot 12-gauge that has no value from a collectors standpoint or anything.

I want to load 12-gauge cartridge in it that have just powder, no pellets / slug. I want to create a rifled full length insert for the barrel that will allow me to breech-load a .357 bullet into the insert forward of the 12-gauge cartridge. I want the area between the insert and the 12-gauge shell to be tapered from the diameter of the 12-gauge to the diameter of the bullet. Basically, it would be the shape of a large bottleneck chamber.

Of course, I am well aware that bad things would happen if I fired a 12-gauge cartridge in this that did not consist of ONLY powder.

Comments? Thoughts? Am I just reinventing something that someone has done before?

[WilliamDahl]

But that would limit the amount of powder that I could use. By doing it this way, I could theoretically at least have a full 12 gauge shell capacity powder charge. Kind of a take off of the 12 gauge from Hell idea.

[fcvan]

I have been looking at chamber inserts for 12 or 20 ga from this company:

http://www.mcace.com/

They have a multitude of calibers in 2 3/4", 10", and 18" in length. I inquired about the rate of twist on a particular caliber and had an email response late on a Friday evening. They appear to be a family owned shop in Alaska. I also viewed some YouTube video of a guy shooting various calibers through his shotgun.

I can see where mounting some iron sights on the barrel would be a great idea to help increase accuracy. I think having a 10" insert for a nominal pistol cartridge in a single shot would be rather versatile combo. Not to mention rather inexpensive.

[WilliamDahl]

12ga necked to 38cal brings new meaning to "overbore". Are you using powder with the strength of peat moss?

Haven't quite decided on the powder yet. I've got some 20mm pulldown powder that I need to find a use for. :)

[WilliamDahl]

And while I'm at it, I have another question. Supposedly the NFA rules say that you have to pay a $200 tax if you want to have a shotgun shorter than a certain length. On the other hand, the Taurus "Judge" has a rifled barrel, so it is not subject to that. Just for curiosity's sake, if some was to scratch some very shallow rifling in the barrel of a 12-gauge could they then make a pistol out of it? I'm thinking that some people might desire to have a 12-gauge size pistol, but since they only want to shoot shot-shells from it, they don't want a twist in the rifling, just let it be straight.

Not that I'm interested in firing a 12-gauge pistol. I've done it with a legal one before and it felt like it nearly broke my wrist.

[2AMMD]

You can cut the shotgun barrel to a minimum of 18 inches legaly (most do 18-1/2 or so to eliminate any question in atf measurement) and use inserts from Guage Mate or MCAC. There may be others out there, but these appear to be the best I have seen. Between the two, the adapters are available in many calibers. This would allow several calibers for different uses. Add open sights or a red dot and you have a great short range multi purpose gun. Just my 2
2AMMD

[Nobade]

And while I'm at it, I have another question. Supposedly the NFA rules say that you have to pay a $200 tax if you want to have a shotgun shorter than a certain length. On the other hand, the Taurus "Judge" has a rifled barrel, so it is not subject to that. Just for curiosity's sake, if some was to scratch some very shallow rifling in the barrel of a 12-gauge could they then make a pistol out of it? I'm thinking that some people might desire to have a 12-gauge size pistol, but since they only want to shoot shot-shells from it, they don't want a twist in the rifling, just let it be straight.

Not that I'm interested in firing a 12-gauge pistol. I've done it with a legal one before and it felt like it nearly broke my wrist.


BATFE says "once a shotgun always a shotgun". So you'd still have to pay the $200 tax to make one. The Judge is a pistol and always will be a pistol so it has different rules.

BTW, the pressure you would generate with your original idea, even using WC872, would likely disassemble a shotgun action as well as destroy a normal shotshell when you fired it. A 35 Whelen has plenty of powder behind a 35 caliber bullet and it only holds maybe 1/2 of what a 12 ga. shell would. And I wouldn't build one of those on a shotgun action either. If you really want to launch a 35 caliber bullet fast, a 358 STA on a good bolt action is about all any normal person can stand. I know I don't like shooting them with full loads!

-Nobade

[Goatwhiskers]

The sheer volume of a fast burning shotgun powder choked down into a small bore is gonna give you pressure problems big time. Couple that with the fact that virtually all of the old single shotguns used cast iron--not steel--receivers and you are looking at a recipe for disaster. A Handi-Rifle with a SB-2 frame in one of the various .35 calibers is a lot cheaper than a funeral and you're here to enjoy it. Your choice. GW

[Skunkworks]

A 12 2½" shell will hold in excess of 200grains of powder and still leave enough case for a starcrimp!

I changed the case capacity to 250grains of water like a cal 12 case will hold.
This is a pure disaster in the making.
http://i295.photobucket.com/albums/mm153/Chickenthief/Skydning/Til%20andre/cal12disaster_zpse5a51178.jpg (http://s295.photobucket.com/user/Chickenthief/media/Skydning/Til%20andre/cal12disaster_zpse5a51178.jpg.html)

[JakeBlanton]

I have to wonder if this might result in one of those "hold my beer" moments. I would like to see what this might do, but from a FAR distance. :)

I have to wonder if you might be better served with just creating a weapon from scratch instead of trying to make a 12-gauge succumb to your desires. Maybe someone along the line of the old breechloading cannons?

Maybe something like this but supersized somewhat?

http://i1.ytimg.com/vi/OVBf3syAnWs/hqdefault.jpg


https://www.youtube.com/watch?v=OVBf3syAnWs