Making 12ga (almost) from hell brass

For a while now I have been toying around with making 3 1/4 in heavy brass shotgun shells. the end plan being able to seat full bore slugs over full cases of powder like regular centre fire ammo, only bigger! something along the lines of a 730 nitro.
Yes I am aware shotguns are not meant to shoot rounds like that, but its part of a bigger plan that includes the heavy rifled barrel I have tucked away and a Greener GP.

Anyway my plan consists of joining 12ga shell heads onto cut down 50bmg brass. my first attempt involved turning the head of the 50 case down slightly with a file and then emery cloth and gluing the heads off of regular shotshells onto them with Epoxy.

First effort

The Exopy I used.
The heads stuck really well when I tried the first one so I knocked up a few more.
But then I hit a snag when I tried to seat primers, the primer pocket are not supported and the primers were all loose.
So I came up with a new plan (and bought the mini lathe) to fit the heads from Magtec 2 1/2in brass shells cut down, I turned the 50 brass down on the lathe until I could press fit the magtec heads on.

Next step will be to fire form the shells using a light load of BB’s.

Seen the prototypes, can confirm, @GUN-DMC swapped brains for more balls.

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The reason I settled on 3 1/4inch was that that was the longest case that would load into the martini action.

Yeah, because shoulders are stupid anyway and need to be punished, ay? LOL. I’m not going near that thing.

@Jim_Fleming talk about that on ya podcast :slight_smile: Intercontinental ballistic shotgun of mass awesomeness.

@GUN-DMC tinker away more in this direction. :smiley: much more productive and interesting.

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Wouldn’t you be better soldering them or better still silver soldering?

Soldering or brazing will likely anneal the brass.

Why not just use the brass shot shells?

Yes, silver soldering would but I doubt soldering would. Solder melts at about 200c. Too low I think

I won’t be soldering at this stage, I will try the epoxy next if I find I need to beef it up or tap a thread on the case and screw the heads on with loctite.

I’m not using the magtec brass whole for this because the walls are to thin to to seat bullets in them without making a die set I think, plus 2 1/2 inch cases are for girls and antiques.
I really want a 12ga from he’ll and I really want a greener GP 12 bore rifle. So this is the compromise between the two.
Plus I like to tinker!

I’d be concerned about the pressure if you are planning to load heavy slug loads as you suggested. Having trouble believing the join is going to hold up.

Me too . That’s why I suggested soldering

Epoxy would be stronger than solder I reckon and there’s no risk of annealing.
The 50bmg case still has it head it’s only the rim that’s turned down and the primer pocket of the magtec brass fits inside the bmg primer pocket.

I wouldn’t be too worried about pressure. The case is really supported by the chamber which is what really takes the pressure. The case is just there to hold all the components in place.

However maybe use a long piece of string to fire the gun the first time.:smile:

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A very long piece of string…

Yeah long string and start with a trail boss load before moving onto 2218 or whatever the ADI bmg powder is called.

I think solder will be several times stronger than any epoxy. Yes the chamber takes the pressure but what if the epoxy fails at the case head/join & leaks. Where will the gasses go?

Shit yeah! Max power charge load her up and get the strongest most bad ass shotgun you have @GUN-DMC ( not the russian door bell )

Safety third!

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Are you just trying to creat a rim so the heavier case works in a shotgun chamber?