Latest 3D Printed Hybrid Design: Cartridge/barrel Integration

Gun Watch ^ | 7 November, 2014 | Dean Weingarten

[marktwain]

Image by Michael Crumbling




The latest 3D printed hybrid uses an old but useful concept: pre-loaded interchangeable chambers/barrels/cartridges.   The cartridge itself has sufficient strength to contain the pressures necessary for propelling a projectile, and is sufficiently long enough to result in a velocity that is useful.

Michael Crumling has created a relatively small round, the .314 Atlas, to demonstrate the concept as used with a 3D printed mechanism.   Here is a video link showing his system being fired:

Link to video at Wired

The extractor groove is likely included to make priming the cartridges easy.

I have thought of this concept myself and it has considerable possibilities for hybrid designs.   Designers need not be limited to a relatively anemic .314 ball projectiles, or to primer activated systems.   The system could easily use percussion caps or electrical ignition.    A simple electrical ignition system could use model airplane engine glow plugs.

As Michael has noted, such cartridges could easily be used in a revolver.   I mentioned such a concept with the hybrid Imura revolver.

You do not need to machine the chamber/barrel/cartridges from scratch.  You could much more easily use common water pipe as the basis for the cartridge, using common taps and drills and commercially available plugs to create the chamber/cartridges.  and have a more practical and powerful system.   Nominal 1/4 inch Schedule 40 pipe has an interior diameter of .364, a very useable caliber.   Nominal 3/8" Schedule pipe has an ID of .493, a nice round ball pistol size.   Nominal 1/2" schedule 40 has an ID of .622, almost exactly 20 gauge.    Mare the cartridge 3.5 inches long, and you would have two inches of usable barrel.  Each chamber/cartridge would then be smaller than a magnum 12 gauge cartridge.

As with Michael's concept, the 3D printer need only supply a usable handle and a firing mechanism.   Even a single barrel/shot design is useful for self defense.  Such designs were used by European armies for centuries.  Add the quick reload possibility of a few spare barrels/cartridges, and the concept is quite practical.   Single shot designs are common in India's black market pistols.

We will likely see more hybrid concepts surface with time and experience.

©2014 by Dean Weingarten: Permission to share is granted when this notice is included.  Link to Gun Watch

[ChildOfThe60s]

BTTT

[ChildOfThe60s]

Technology is making this even more relevant every day. No wonder the statists are getting nervous.

WHAT GOOD IS A HANDGUN AGAINST AN ARMY?
http://www.jeffhead.com/liberty/handgun.htm

[ClearCase_guy]

I would love to see amateur gunsmiths all across the country playing with this technology, thinking up things that no one ever thought of before. We might see some really interesting advances, which anyone could then go and produce in private.

[eartrumpet]

A simple electrical ignition system could use model airplane engine glow plugs.

I tried that 20 years ago with a black powder design. The center of the glow plug blows right out, only good for one shot.

[Bogey78O]

Here’s an idea, use a 3d printer to make a front sight attachment for 1/2in pipe. Saw off the threads on a 2’ length of pipe, drill through the cut end and set two screws to act as a rotating lock. Cut a 3/4” nipple to hold the rotating lock for the barrel.screw the nipple in to a 3d printed handle/firing mechanism.

Fire, rotate, pull, whip the cartridge out, reload, rotate, repeat.

[marktwain]

“I tried that 20 years ago with a black powder design. The center of the glow plug blows right out, only good for one shot.”

I used it in a number of pistols, both single shot and multi-shot. I got several shots out of them, though I did not shoot them to destruction. I noticed, though, that if you did not clean them very well, the black powder residue caused corrosion in the glow plugs, weakening them and causing blow-out.

Did you use yours in a pistol or a rifle? That might make a difference.

[eartrumpet]

I tried it in a scrap hunk of barrel as proof of concept. When I ran out of glow plugs, I ran out of desire. It was probably 14”.

[W.]

Used to have a copy of the SF Handbook TM 31-210 which explains the basics before 3D. Been online for years, lots of fun-looking scary stuff. [For entertainment purposes only!]

[dangerdoc]

My plastic gun fires 10 mm auto.

[marktwain]

The barrels that I used were made from nominal 3/8 galvanized pipe, and were about 5 inches long. I used patched .45 cast bullets. They exited at about 430 fps.

Measured ID was about .480, but schedule .40 is shown as .493. A little wadding would work well.

Typical black powder “derringer” velocities.