REAL firearms research - explosive casings

[Bill_Rights]

Yes, many big guns (crewed cannon, artillary, ship guns, etc.) use what is caseless ammo, in one form or another. Thanks, CapnMac, for the lesson on that.

LaserSpot said: I don't think a bolt could be designed that would seal the chamber well enough and work with an existing barrel. Maybe they should go to a semi-caseless design that uses a metal and plastic head to hold the primer and create the chamber seal.

Early in this thread Special K was kind enough to point out http://en.wikipedia.org/wiki/Caseless_ammunition, which was pretty good and talked about rear-sealing of the firing chamber. It IS a problem. One thing the Wikipedia article said was:

...the French Chassepot solved the leaking breach problem with the addition of a rubber seal to the bolt.[8][9]

8.^ P.O. Ackley (1962). Handbook for Shooters & Reloaders vol I. Plaza Publishing. ISBN 978-9992948811.
9.^ See main article, Chassepot, for references

Also, Jim Watson remembered the Voere (German/Austrian) example.

Voere had a bolt action with bullet molded into a caseless propellant charge. There was a groove around the propellant cake and an extractor on the bolt head so you could unload without firing the shot in the chamber. A bolt action sporting rifle, it was not likely to overheat the chamber. It was electrically fired; two 15 v batteries claimed enough for 5000 shots.

It would be interesting to know what solution Voere had for breach sealing.

I think it is a problem but not a fundamental problem.

 

[RSC]

Abrams ammo

"Isn't the ammo for the Abrams "caseless?" Has a small ring of metal at the breech end with an extractor groove, I think?"

Yep, the Rheinmetall Rh120 MBT Cannon uses ammo that has a partly selfcombustible casing (also used in the Leo II MBT). Most of the cartrige consists of a cardboad like material that goes up in smoke when fired. The bottom of the cartridge is metal (looks like an ashtray with a spike) and is the only part that is being ejected after the shot. As the highest cadence you can achieve with a human loader is about 1 shot every 3 to 5 seconds, you don't have to worry about heat buildup in the breach, actually the hydraulic recoil brakes are going to fail before the breach gets hot enough for a round to cook off by itself. Another fringe benefit was the ability to poke a meat thermometer through the casing into the round to measure the internal temperature of the round.
Having said that, the the heat management problem of the G11 was solved in the latest versions. I was part of the field trials back then and this gun was incredible, a true shooting machine. It looked like crap, but it made holes where you pointed it at and was extremly light compared to the G3.

 

[4thPointOfContact]

Just throwing this into the mix: ...
Anyone remember the Dardick gun?

It utilized a revolving cylinder with three "tround" chambers. Tripling the number of chambers might alleviate some of the cook-off issues.



Using a cammed ejector to kick the round out sideways could solve the problems of no extractor grove and cook-off. (Finding a design that would resist chamber pressure might be challenging, though).

The real drawback to the Dardick system that I've seen is that
a) it feeds from an off-center location, one-third of a revolution from the firing position. [Edit: Actually, it could work from any position, even on top. The firing position could be at bottom dead center and still work.]
b) in order for the trounds to smoothly slip into a chamber there can't be a lip on the magazine, so holding the trounds in place is problematic.

Hmmm... combine tround technology with a horizontal (P90) magazine, then make the magazine seal by twisting closed the 'feed turret". To load, you insert the feed turret into the rifle and then swivel the magazine into place which opens the feed path??? Not too far out aside from having one extra moving piece on the magazine.

 

[Bill_Rights]

4thPoint,

I am not sure I follow all the details of the tround technology, but would it reduce weight carried by a foot soldier, for an equivalent firepower? That is the main point of the current Army RFP.

 

[Shadow 7D]

yeah when you look at the basic load of a soldier, with body armor you now add 30 pounds to what was traditionally carried, weight = reduced speed and range (exhaustion, less supplies) so every army wants to trim what they can to win battles, and 300 brass cases would be a start.

 

[Sunray]

"...Trying to fix something that isn't broken..." Happens all the time. That's why we have hordes of very similar cartridges. All of which the gun rag writers call the best thing since sliced bread. It's mostly a 'bring out new stuff or lose market share' thing.

 

[4thPointOfContact]

From what I've gathered about the tround technology ....

Caseless ammunition probably wasn't even on the radar screen when the tround was developed, but combining the two technologies might prove possible (with the resultant weight reduction). I can envision at least getting rid of most of the brass except perhaps for the primer itself. Get some 110% reliable electronic ignition and you could eliminate that as well.

It is suggested that it allows easier, less complicated feeding since the tround slips sideways into the chamber without regard to orientation, instead of having to be forced from the magazine into the chamber.

Weapon weight might also be reduced since there would be no heavy reciprocating bolt / bolt carrier, only a revolving cylinder.


It's all theoretical, but isn't that half the fun of trying to brainstorm solutions?