Thanks Adam S. for sharing this.

Adam gets some interesting customers at his work. One thing I miss about working behind the gun counter is the oddball stuff that comes in once in a while. One of Adam’s customers brought this in.

One of my customers said he “invented” a new caliber. It was a baited statement, but I bit anyways and asked, “What’d ya make?…”
He pulls out the round on the left hand side from his pocket. He is a reloader and a machinist and he somehow managed to cut down a piece of .50 BMG brass, steeply shouldered it, and stuck a .17 caliber bullet on top.
He’s been going around screwing with his friends saying its the latest and greatest .17 Hornet 2.0ย or saying I just bought a gun in Rock Island Armory’s newest caliber: .17 TCM!!! It’s been having some feeding issues, but I’m sure they’ll work it out!
It was pretty hilarious to talk about, but now that somebody made this ridiculous caliber…. I really want to know what would happen if you fired it! His “demo” round had a live primer in it with no powder…



  • Tim

    Awww no u di’in’t……

  • gusto

    feeding problems?
    just make it a ruger nr1 type rifle and voila solved!

    • Xtorin O’hern

      a T/C encore could do it no problem

      • autofull– kevin horning

        my reloading buddy invented the 50-30. ya could not chamber it but it sure was the talk of the c3 shop i had.

  • nova3930

    SO how bad does it burn barrels

    • Dr. Daniel Jackson

      Burns them down like a forest fire,there is a reason we don’t see many cartridges in the 5K FPS range, barrel life being one of the major factors.

      • nova3930

        I suppose the facetious nature of my comment was lost along the way…

        • Marc

          Love the facetious usage. Underrated word.
          Garb is another. Why don’t people discuss the garb they are adorned in more?

          • Marc

            Fine, I had a few drinks with dinner. Sue me.

          • it’s just Boris

            Gab about garb? How gauche. ๐Ÿ˜‰

          • Evan

            Because discussions of garb are banal.

      • noob

        I always wondered what a hand weapon that was pretty much just a large metal shield that fired a tiny explosively formed projectile at 30,000fps would be like. The mass and shape of the weapon prevents you from dying as a thin flat disk of high explosive turns a sheet of steel into a finned dart inches from your hands.

    • Paul White

      You get a free barrel with every 5 rounds!

      • oldman

        But only if you survive shooting 5 rounds my guess is after two you loose interest fast. Betting it would be a bit of a thumper.

    • GaryOlson

      Use a powder which burns so slow it almost smolders. Find a 48″ kryptonite lined barrel with a liquid helium cooler. The bullet will be so fast it will change the nature of metal and be frictionless — just like Superman.

      • Edeco

        Yep, bullet turns to plasma, glides on a subparticle foam of electrons. There’s no friction but time speeds up slightly in the vicinity.

    • Edeco

      Due to the extremely efficient shape which contains all of the reacting propellant, it’s actually easier on barrels than 38 Spl.*

      *yes I’m making stuff up.

      • noob

        another round for Nate’s Modern pdw calibers series?

    • When they say “single shot”, they mean “single shot”.

  • Caffeinated

    That 50 BMG primer could probably get that projectile moving at a decent velocity!

    • Matt Shermer

      Don’t pass that off so casually, there might be something to that worth investigating, a .22 to .25 caliber bullet propelled only by a .50 BMG primer, it needs practically no case because there’s no powder. You could probably use a .223 Remington cut short as the parent case with a larger diameter primer pocket…

      • Deplorable-Shocked&Amazed

        Interesting concept… add 10grains of bullseye

  • Martin Grรธnsdal

    Lawmakers in california are besides themselves. Another evil caliber to ban!

    • BNG

      Yea, in california only are legal all type of depravations, and human slavery, but freedom and culture arent California friendly.

  • RSG

    Forgetting about chambering, feeding and accuracy for a second, but that much powder in that modified case, behind that pill, is easily a 5000fps projectile.

  • SP mclaughlin

    “Mutated 12.7mm cartridge recovered from the Chernobyl Exclusion Zone, 2007 (restored in color)”

  • E.D. Sartin

    I actually have an old (60’s) loading manual with some wildcats in the back with the .22 Eargesplitten loudenboomer being one. It’s a .50 full length necked to .22, with loading data to 4000 fps.

    • Noishkel

      Good lord, that slug would pretty much pure plasma with that much power behind it. XD

      • noob

        In the 40 watt range?

      • Tierlieb

        You more or less described Ackley’s problem when he tried to cross the 5000fps threshold.

        It did not turn to plasma, but the bullet was so fast the the rifling sheared/melted off the material pressed into the groves when using pure lead bullets and tore off the copper jackets of jacketed ammo, if I remember the stories correctly.

        • Sam Pensive

          Guess they need a shell with stabilizing fins like our tanks have that fire (smooth bore) and the sabot starts to rotate post emergence from the bore.

          • Deplorable-Shocked&Amazed

            Hard to pull off in a .223 dia. Now 30 cal might be doable

        • Chrome Dragon

          And this is why we need Teflon coated bullets.

          • Deplorable-Shocked&Amazed

            Should have waited before i said that, you had Teflon covered

        • Deplorable-Shocked&Amazed

          Solid copper or solid alloy projectiles?

        • Deplorable-Shocked&Amazed

          Wow. Maybe less of a depth for rifling since the bullet is just molten metal… solid copper projectiles? Teflon COATED titanium projectiles… at what temp does Teflon melt?

          • Secundius

            About +621F…

          • Secundius

            I suspect “Tungsten Carbide” Projectile, if there’s ANY chance of Killing Anything at a Great Distance…

        • Just-a-guy

          I know we’re just goofing off here, but I wonder how much closer you could get with the “gentler” 5R rifling that doesn’t deform the projectile as much as traditional lands and grooves?

          • Secundius

            Were still talking about a 4.5mm Projectile “Rattling Around” inside a 13mm Barrel before IT even leaves the Barrel…

    • Giolli Joker

      It was based on a .378 Weatherby Mag., not .50 BMG.

      • E.D. Sartin

        Goes to show how long it’s been since I opened that book and laughed ๐Ÿ™‚

    • Blake

      Yep, 22 Eargesplitten Loudenboomer is on Reloader’s Nest:
      Ackley had a great sense of humor ๐Ÿ™‚

    • Sunshine_Shooter

      4000 fps is .22-250 speeds. Couldn’t the EL get somewhere around 4,500+ fps?

  • Xtorin O’hern

    can someone please re do that but with a more gentle neck and with like a .416 bullet? that could be a cool little round

    • gordon

      Oh come now, let’s not get ridiculous;-)

  • Keiichi


  • Jake Franklin

    “Nvr ben done B4”

  • Disarmed in CA

    Cheap practice rounds for your Barrett!

  • Evan

    I’ve seen a full length one of those at a gun show. Someone ought to build a gun around this and try it out. You know, because science.

    • I think you mean SCIENCE!

      • QuadGMoto

        I think you mean Redneck SCIENCE! ???

      • Evan

        I do, but i don’t know how to do the bold or italics.

    • Jeff

      Yeah, I want the full length version.

      • Deplorable-Shocked&Amazed

        I have a friend who has been wanting one of those his whole life

  • Edeco

    There’s been a trend, for various reasons, toward short, fat cases for a given capacity. I’d like to see it tested to the extreme… with a string, from a distance and from behind steel plate.

  • lol

    well it “is” closer to the near ideal “square” bore for burning substances (see the trend towards bore width x bore stroke in engines being nearly the same)

    not sure about .17 though. neck up a bit for a .30 caliber heavy bullet, say 174 grain or 180 grain, have a custom match barrel built (30 caliber rifling in a 50 BMG barrel blank) and you could maaaaaybe have a go at it in the 1,000 yard competitions.

    it would certainly have a very positive headspace on its shoulder.

  • Southpaw89

    The .17 Winchester Super Short Ultra Magnum.

    • Winchester Alternate Super Type Extreme-Expansion Magnum.

      Tell me you couldn’t sell crate after crate of WASTE-EM cartridges.

      • Nathan Alred

        Only if you put the neon-green zombie-slayer polymer tip on it.

  • nonobaddog

    That is funny but it has been done before. I remember a well known reloader at the time doing this back on either rec.guns or rec.reloading back in the usenet days. That had to be back in the 80’s. I don’t remember if he ever made a barrel for it but it would not surprise me.

  • Gary Kirk

    Exactly why? Why?? Are we trying to reinvent the hand grenade??

  • Giolli Joker

    Needs more “thermos bottle” shoulders.

    • oldman

      Ackerly improved shoulders.

  • Tom Currie

    Reminds me of an article I read in some magazine many years ago about the wildcat cartridge .177-40Bofers, designed specifically for hunting the dreaded Naulga while doing minimal damage to the hide.

  • Blake

    Mirror, mirror, on the wall
    who’s the barrelest burner of them all?
    .17-50 is my name
    shredding rifling is my game

    Incidentally, Adam, did you ask him what the twist rate was?

    • Peadair

      1:1.00001 twist ๐Ÿ˜€

      But probably the safest twist would be 1:100

  • mrpotatocat

    Wait for gun store fudds to come in and try to sell them the latest greatest caliber!

  • sadlerbw

    Gah! Turn that neck down son! You’re just trying to hold a 20gr. bullet in the case, but you’ve got enough neck tension there to choke a water buffalo.

  • matthew hornback

    good catalog ya got there!


    The man nealy made an oil can dropper out of a 50BMG casing!

  • scaatylobo

    I would bet that that “round” would most likely MELT as it left the bore.
    IF it did not melt IN THE BORE .

    • alex archuleta

      My thoughts exactly lol

  • Seth Hill

    Ok, where can I find 20MM Vulcan and 30MM brass? Better yet, 105mm howitzer shells.

  • Some Rabbit

    When I was a boy 45 years ago, I’d hang out at the local gunsmith. He too had such a joke round sitting on the shelf behind the counter. I also suspect that the casing is turned out of solid brass because there’s no way you’re gonna neck down .50BMG to .17 without the shoulder collapsing.


      When I was a boy in the 50’s I bought a 20 lb custom made 220 Swift. It has a 1.25″ Douglas Bull barrel, Bull Pup glass bedded mahogany stock with thumb hole with cheek rest, and Lyman Super Target Spot scope.
      My most memorable experience was shoot

  • Gary Griffiths

    Or for the ultimate in velocity: The .17/French 75mm! Real S-L-O-W burning powder — something on the order of charcoal! ๐Ÿ˜‰

  • Diver6106

    I think the bullet would turn into plasm as it exited the barrel. HEY, this might be a round for the first PLASMA RIFLE.

  • Nathan Alred

    Wonder which end is more dangerous?

  • Marcus Toroian

    My favorite LGS has a full length 20mm vulcan cartridge necked down to either .30 or .338 caliber on display. I’ll grab a picture next time I’m there.

  • Goody

    Would be lightning out of a lever gun

  • alex archuleta

    Well if it’s anything like the lego head in a .40 brass casing, I give it a few more days and there will be a video somewhere of someone firing something like it.

    • VT Patriot

      At the annual Darwin awards dinner, this would be the winner of the decade.

  • romney2011

    I saw a cartridge decades ago on the same principle. I was necked down about 3 times. Something like a .50 x .30 x 22 x 17. Speed was bad assed and shot flat forever. Nothing much new under the sun.

  • Richard Huggins

    Before I retired from law enforecement one of my sergeants did reloading and made an ” Idiot’s 45-38″. The case was a .38 spl. and the bullet was .45 APC. He was not able to come up with a gun with which to fire it though as he was not able to find a way to fire it with the case going into the chamber first.

    • gregge

      Put the chamber in a sliding breech block, with a clip that rises to catch the rim. Then when you move the lever (’cause a lever gun would just be the coolest for this) the, uh, inholder, (opposite of extractor) drops down as the block slides back and tips down at the rear to aim its mouth up and clear of the barrel.

      As the block finishes its travel it releases an ejector pin to pop through the inholder hole, kicking the case out, forward and up. Forget mounting a scope, unless the action also has a deflector that pops up as the action is opened.

      The next stage has the block dropping at the front to receive a fresh round from the tubular magazine, simultaneously cocking the ejector and firing pin. Pull the lever back and the block rises and goes forward into battery, inholder up and in the cartridge groove, ready to fire.

      The paths taken by the block as it moves rearward and forward need not be the same. Have guide pins on its sides that go around a precisely shaped track, with sprung gates to ensure it goes the proper direction.

      Not impossible to have a cartridge larger at the dangerous end, just a bit impractical. Anyone have SolidWorks to model this? A 3D printed demonstration model would be very interesting.

  • Secundius

    How do you Control Trajectory of a 4.5mm Projectile (Bullet) coming out of a 13mm Inside Diameter Barrel…