12 gauge from Hell

Discussion in 'Large-Bore/Small-Bore Rifle/Shotgun' started by That_Guy!, Jan 15, 2019.

  1. That_Guy!

    That_Guy! Well-Known Member

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    Very obscure and not well know wildcat, but I'm convinced it is one of the most versatile cartridges ever created.

    Let me explain.

    Essentially you convert a 12 gauge slug gun into a big bore rifle. You do this by using a very slow rifle powder (to keep pressure low) and brass 12 gauge hulls. There are some stipulations though. The brass shells must be thicker than normal stamped hulls, meaning they are lathe turned. And the shotgun has to be beefy. A bolt action savage and an H&R ultra slug (which is what I'm using) are great choices. The savage can take quite a bit more pressure than the H&R, but they are harder to find and more expensive. The chamber needs lengthened to 3.5" (or 3.85" for the savage). With the slow burning powder you get insane velocities and muzzle energy. One load calls for 240 grains of H50bmg and shoots a 600g solid at over 2500fps. We are talking similar if not more energy than a 700 nitro express. The beauty is, since it's just a lengthened chamber, you can still load up conventional 12 gauge ammunition and hunt squirrels one day to any game on earth the next. This also prevents this build from being classified as a destructive device by the ATF since its still technically a shotgun.

    I just got the ball rolling on the build so it will take some time to get it completed. The majority of the wait is for the hulls which are made to order by RMC.

    While I can use slugs, I wanted something more purpose built with better ballistics than a hunk of lead. So I contacted Lehigh Defense about some custom projectiles. I am having two types made. A .729" (bore diameter so no sabots) 600 grain copper bullet and a 1085 grain solid copper bullet designed for max penetration. I think we are going with their extreme penetrator/extreme defense design for the rounds. They should be absolutely devastating on game.

    So far my costs are

    $450 for gun
    $150-$300 for chamber job (estimate)
    $285 for 20 3.5" hulls ($105 for 10 + reloading kit)

    The bullets are a very pricey endeavor however and I will post my correspondence with the engineer when I get home.

    Super excited for this to come full circle. I love big bores more than I can say. A 700 nitro express can run a guy well over $100k. This is a fraction of the cost and is waaay mor versatile. I have honestly never been so excited about a cartridge in all my life.
     
    Last edited: Jan 15, 2019
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  2. Alpo

    Alpo Well-Known Member

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    Do you expect accuracy?

    There's a reason people went from smoothbores to rifles. A smoothbore won't be accurate more than a hundred yards, if that far.
     
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  3. 68c15

    68c15 TFFWPP President Supporting Member

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    can you get a rifled barrel with 3 1/2" chamber?

    That's gotta recoil pretty bad. I kind of want one.

    My 12's I have run 1 5/8 oz goose loads, but those top out at 1600fps (ish). Doing those in summer is NOT fun
     
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  4. That_Guy!

    That_Guy! Well-Known Member

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    The slug gun has a rifled barrel.

    The h&r comes rifled. The chamber lengthening is just as simple as reaming it out. Pretty common thing to do. As for recoil, yes it is definitely going to be stout. As the gun sits stock it's under 11 lbs. I will be definitely adding weight and recoil reducers with an extra thick pad. The 600 grain loads at 2500fps have around 120-150 ft-lbs of free recoil energy in a 13lb rifle. This will definitely cause shoulder injury if not properly held.
     
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  5. That_Guy!

    That_Guy! Well-Known Member

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    As for accuracy, I really will never shoot it much further than 50 yards. But with the barrel being rifled and the rounds I'm gonna use from Lehigh, I expect it to be very accurate for a big bore rifle
     
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  6. That_Guy!

    That_Guy! Well-Known Member

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    Here are a couple snips from my email chain from the engineer at Lehigh Defense. This will give you an idea on how much a bespoke bullet costs. Very expensive, but I can live with the $600 investment to have a reliable source of bullets when I need them.

    Screenshot_20190115-063214_Email.jpg



    Screenshot_20190115-081645_Email.jpg
     
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  7. Kvasir

    Kvasir Well-Known Member

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    Could come in handy for felling trees. :D
     
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  8. Jester560

    Jester560 Well-Known Member

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    TRex killer from HELL! I can't wait to read more.
     
  9. Kvasir

    Kvasir Well-Known Member

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    I wouldn't want to be the first guy to shoulder that monster.
    My M85 Styer cavalry carbine is all the punishment that I can take anymore.
     
  10. That_Guy!

    That_Guy! Well-Known Member

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    Here are loaded cartridges. The first is a 3.5" 20 gauge from hell, second is a 3.5" 12 gauge from hell

    The other two are 3.85" 12 gauge from hell. One is made from a modified 50bmg case and the other is from RMC. As you can see, they are more like rifle cartridges than shotgun slugs.

    20181229_114344.jpg
     
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  11. That_Guy!

    That_Guy! Well-Known Member

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    Oh and here is the gun I'm using. The receiver with the pistol grip is a custom singleshot 12 gauge pistol I'm making (waiting on my stamp but can still throw on a barrel as long as I meet length requirements) oh and it will NOT be chambered for 12ga FH for obvious reasons lol a broken wrist isn't on my list of fun things.


    The slug gun comes with a 24" 1-35" twist. I may have a custom barrel made at 30" with a 1-20" twist to help gain velocity. As for sights, it comes with a scope base, but I might opt for Express sights.
    20190109_171937.jpg
     
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  12. joe45c

    joe45c Well-Known Member Supporting Member

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    OOH, they hurt just looking at them!
     
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  13. Alpo

    Alpo Well-Known Member

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    Not in a rifled barrel. Shooting a shot charge down a rifled barrel produces a donut-shaped pattern, with a large hole in the middle.

    This is why I presumed it was smoothbore. Shooting small game with a shot charge in a rifled barrel is a waste of time and lead.
     
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  14. Jester560

    Jester560 Well-Known Member

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    I had the Pardner 10ga Turkey gun and it hurt enough to shoot. I can't imagine that thing especially with 1000+ grains of projectileo_O
     
  15. That_Guy!

    That_Guy! Well-Known Member

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    You are right, but you can still throw on a smooth bore barrel. Still one gun, to do it all. Beauty of the H&R :) point being though, increasing the chamber length will not have an effect on chambering a regular 12 gauge slug. So while I will be increasing chamber length to accommodate the 12ga FH, I can still shoot a box of Winchesters.
     
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