Invicta System

[I'll Make Mine]

There seem to be folks here older than me, who might remember the Invicta System revolver, patented in 1973 but never came to market. They used a barrel with a smaller bore than the cylinder, and a cartridge that carried the bullet in a polycarbonate insert that stopped and sealed against the barrel, closing the cylinder gap while the bullet exited, then relaxed back to avoid locking the cylinder as bottleneck cartridges are prone to do. I've always thought they disappeared because of the liability potential of selling a gun with a standard cylinder but smaller barrel, though I wondered why manufacturers didn't just build a revolver with a proprietary/oddball chambering to prevent (say) loading a .357/22 Invicta with standard .357 Magnum ammunition -- something like a .365 cartridge diameter, it'd be oversize for a .32 and too small to chamber a .357 or .38, but give performance similar to the .357 based round.

Regardless, the patents are long expired, and I've been wanting for a long time to build an Invicta revolver. I've got a Dan Wesson Model 15 in .357 Magnum, the model that was the original test platform for the Invicta system; my plan has been to get a .22 centerfire barrel blank, turn and thread to fit the Dan Wesson frame and barrel nut, but leave the barrel longer, profiled to pass the nut but give a 10" barrel in the 6" shroud I have (much cheaper than trying to find an original 10" barrel shroud). I figure one ought to be able to get ballistics roughly equal to a .221 Fireball, from a six-shot revolver.

You'd reload with regular .357 Magnum dies, though you'd need a way to pull the inserts before sizing/decapping, and you'd pre-seat the bullets into the inserts before loading them into the case like a long-seated wadcutter. No case forming, no hard to find brass, and after a day shooting .22 bullets at (for a revolver) extreme velocity, just change the barrel back to the .357 and your home defense revolver is back on duty.

Anyone built one of these? Any special pitfalls to watch out for?

[BLTsandwedge]

I can't help with the engineering- I won't even change a spring in a K-frame because I'm a half-wit. Sales & Marketing is a different story. If you wanted this to be a commercially viable project, I'd recommend finding out why the .22 Jet failed to sell and use that as a case study. My gut tells me that proprietary ammunition will face an insurmountable challenge unless there is something absolutely incredible about the product- some favorable attribute that would make the revolver appealing to prospective buyers. We know the general population of prospective firearms buyers to be a pragmatic lot. I believe there'd need to be readily available choices in ammunition and reloading equipment/components. Selling to their (our) interests would be the #1 priority in the R&D phase. Financially successful case studies would be needed too- what made so many of the erstwhile Ackley wildcats become commercial success stories?

And then there's that pesky little detail known as raising start-up capital- you know, where you sell your soul and the souls of your children and their children to the one VC out of 300 you'll call on..........but, that's how new products get developed and that's how new millionaires are minted.

[MtGun44]

+1 on capital, uniqueness and throw in extreme conservatism of handgun buyers and it will
be tough. Benefits must be clear and LARGE. Good luck, it will be at least interesting as
a project, even if it ultimately goes nowhere commercially - again.

Bill

[I'll Make Mine]

Actually, I wasn't thinking about building these commercially, either as complete guns or conversions for existing revolvers (Dan Wesson or not); I was just planning to make one for my own enjoyment, using standard .357 cases. If I could afford a spare cylinder and the work, I'd consider sleeving and boring undersize -- looks like a case based on .32-20 is the closest I could get to my preference, at .354 head size; that should, at least, be safe against accidental chambering of rounds with full size bullets in any .357-ish size, and oversize enough for .32 Colt or S&W family rounds that they'd rattle and obviously not fit.

The kind of pitfall I was concerned about in putting a .22 barrel on a .357 Dan Wesson is what happens with the portion of the barrel that protrudes past the front nut? A ten inch tube is a practical minimum, if one is after velocities above 2000 ft/s from a handgun (.221 Fireball, as I recall, shot about 2200 from the 10 inch XP-100), but the barrel forward of the nut can't exceed about 5/8" diameter; I don't know if it would be stiff enough in a four inch unsupported length to give good accuracy (or alternately whether it might even be flexible enough to cause fatigue cracking near the nut -- a potentially dangerous situation).