$ ammo = resurrect caseless ammo?

[230RN]

"have the firing pin strike the bullet at the waist"

?

Do you mean "the heel," or "the base?"

 

[Phil DeGraves]

Caseless ammo has been around forever. It's called cap and ball.

 

[RyanM]

Here's my thought for a 22 caseless. Put the priming compound on the heel of the bullet, and have the firing ping strike the bullet at the waist. The 'primer' is part of the projectile and gets expelled. The propellant is consumed.

Conversely, you could put the primer in the base of the bullet, and use a long pin (a la needle gun) that passes through a hole in the propellant.

Problem with both of those is sealing the firing pin hole.

 

[zoom6zoom]

If caseless ammo really took off, they'd have to cancel CSI:Wherever.

 

[230RN]

Problem with both of those is sealing the firing pin hole.

Not insoluble, just an engineering task --see my remark about rollsocks in post 23.

You could have a diaphragm* with a pin or bump** in the middle such that when the "flat" face of the bolt hits it, it drives the diaphragm with its firing pin (or bump) into the primer. As the bolt closes and locks, the diaphragm acts as a seal, much like the "mushroom pads" in large naval rifles work. Or, better, the bolt seals against the diaphragm, then a flat-ended firing "hammer" (rather than a pin) strikes through the bolt face and hits the diaphragm and drives its attached "pin" into the primer/priming pellet.

(See pic above of the 16" breech mechanism. The mushroom pad can be seen at the upper end of the interrupted-thread breech block.)

Other possibilities are workable.
******
* A diaphragm is just a special case of a rollsock.

** I prefer the term "boss" rather than bump, but bump is more readily understood.

 

[Gifted]

Why bother sealing at all? Use that blowback as part of your action's operation, and make sure it seals tight enough you're not wasting too much. An AR's action is contained, and so you'd not be worried about having it blow back in your face, just about loss of efficiency. Delay the blowback a bit, but don't worry about a total seal, just make sure your gun can handle the carbon. A precision gun would of course, need more sealing, since the tolerances couldn't be made loose enough to deal with the filth without loosing accuracy, but you pay more for those anyway.

A semi wouldn't have the gas piston, it would use the gas blowing back through the action to power it, and it would otherwise be tight enough not to loose too much power, or be loaded extra to compensate. A bolt or lever action would seal as best it could, then shield the edges to direct the gas in a safe direction.

I kind of like the idea of a piezoelectric system. A crystal in place of a primer, and you could make the base much stronger, possibly using higher pressures as mentioned. Putting the crystal in the action would be better. If a true caseless ammo comes out, a gun like the AR can simply get the bolt swapped out for one that has the electric system(shouldn't be hard to make it drop-in), and new barrel for the new ammo(don't know that you'd mess with a necked case like current rounds). Something like a 10/22 would need a new bolt and recoil spring, but that's about it.

I do agree that we'd see more steel or polymer case ammo though. This could serve as a first step, with the remote piezoelectric system put in, with the contacts on the cartridge. Then later you swap the barrel and magazines for the caseless ammo. The biggest problem with polymer is again heat though. If your chamber gets too hot, the plastic is going to melt in. That brings up a question of what you're going to do when a case partly melts in the chamber, or are you going to use a plastic expensive enough to handle it?

 

[PAshooter]

Already in development. Biggest driver, however, is weight, not cost.

Since when does Uncle Sam care how many of your tax dollars he spends?

But cut ammo (and weapon) weight, and the soldier can lug a lot more firepower into the fray.

http://www.aaicorp.com/New/Advancedprograms/LSATps09-12-07b_1.pdf

 

[Scanr]

How the heck would the kalifornian's micro stamp it?!?!? This would drive the governator and the rest of the libbies nuts trying to figure out this one.

 

[AirplaneDoc]

Think I will stick with hedge funds and futures before I go to caseless ammo

 

[Sharps-shooter]

I'm getting an arquebus, myself. It was that or a .458, and the ammo price was part of what decided it for me.

The arquebus is a matchlock-- It just has a touch-hole, and when you pull the trigger, a piece of burning fuse gets touched to the touchhole, which sets off the charge. No case and no separate primer.

The arquebus is going to have cherry wood stock and brass furniture and a 42" 12-bore barrel, and be real heavy. But I've seen some muzzleloading guns and rifles lately that are very modern looking, even tactical. I wonder if rising ammo prices are making black powder shooting more popular?

 

[novaDAK]

How the heck would the kalifornian's micro stamp it?!?!? This would drive the governator and the rest of the libbies nuts trying to figure out this one.

They'd just simply ban them...worked for everything else...
I think that before we start developing caseless, we'd just use alternative materials like plastic.

 

[230RN]

Gifted said,

Why bother sealing at all? Use that blowback as part of your action's operation, and make sure it seals tight enough you're not wasting too much.

Definitely a "divergent" idea worthy of pursuit, if we can keep in mind the 50- 60,000 "psi" peak pressures involved in rifles and 15- 25,000 "psi" in pistols.

(Aside) And one of John C. Garand's first semiauto designs was an action that unlocked the breech by the setback of the primer on firing, like a little piston. Talk about divergent thinking.

Gifted also said,

I kind of like the idea of a piezoelectric system. A crystal in place of a primer, and you could make the base much stronger, possibly using higher pressures as mentioned.

Gotta watch that one. I believe most of the high voltage piezo crystals are ceramic, but I could be wrong. You would not want ceramic debris up your bore... can anyone enlighten me on that?

PAShoote commented:

Since when does Uncle Sam care how many of your tax dollars he spends?

I believe one of the original major justifications for going to .308 Win (7.62 NATO), was to save on brass. However, I basically agree with the sentiment that our Government is a bit spendthrifty.

Shauner wisecracked,

How the heck would the kalifornian's micro stamp it?!?!? This would drive the governator and the rest of the libbies nuts trying to figure out this one.

Tee-hee, giggle-giggle, nyah-nyah!

Sharps-shooter quipped,

I'm getting an arquebus, myself. It was that or a .458, and the ammo price was part of what decided it for me.

I agree with what novaDAK said on that one, i.e,

(A)They'd just simply ban them...worked for everything else...

(B) But I think that before we start developing caseless, we'd just use alternative materials like plastic.

I agree on both points. With respect to B, some good starts have been made with AL and steel cases. Despite some of the complaints about aluminum-cased ammo, I don't think these are a result of design concept --to my mind, they're mostly manufacturing problems and problems with tiny extractor hooks ripping off rims. After all, the ammo was designed to be cheap in the first place. I suspect, but cannot document, that some alloys (or future alloys) of almuninum might be suitable for reloadable, Boxer-primed aluminum cases. (I worry a little about the abrasiveness of the inevitable Al2O3 which goes along with every aluminum alloy, though.)

Polycarbonates seem to look promising. Perhaps a sputter-coated thin inner liner of metal might help out here. After all, if you can burn a hunk of hamburger in your microwave without destroying the "microwave-safe" container, somebody must have an idea as to how to make heat-resistant plastics.

And we've been galumphing along with steel cases, which actually seems to work allright in guns which were designed for them, I guess. I note that Wolf was pretty sensitive to the varnish issue and apparently changed the coating to a teflon-like substance in later manufacture.

After all, one of the original designs for an autoloader (the Johnson Autoloader in .276?) had little oiler pads in the receiver which oiled up the cases as they were fed into the chamber to aid extraction. And later, the cartridges were hard-waxed for the same reason, as I recall.

So all in all, I guess if we had to change to something besides brass, we could probably make do. We are fairly flexible what kind of fussin' and fumin' we have to go through to go bang.

 

[Wolfgang2000]

H&K spent most of the 80's working on the caseless round. They couldn't over come the fouling (chamber) and heat problem. IIRC

IMHO we will stick with what we have till they prefect the hand held rail gun or a energy thrower. You know the one in the 40 watt range.

 

[White Horseradish]

Well, if you're going to do away with the case, might do away with the powder. Go to liquid propellant.

How about a diesel gun? Spray oil into chamber, sprung piston compresses mixture, it goes bang, slug goes forth, piston gets recocked for next shot. You could probably run on vegetable oil and market it as a green gun.

 

[2E8B]

We just need to bring back the gyrojet That would solve the crisis. We would just have to start talking HOA (hours of angle). :-D

 

[Wes Janson]

No, what the gyrojet REALLY needed was modern manufacturing methods. Or for that matter, bring back the Dardick and Tround concept. Then again, I suspect that as you make the shape more exotic, creating a reliable feeding mechanism becomes difficult.

What if the polymer sabot is also the case?

 

[BHPshooter]

Aside): Many moons ago Herter's had an all-plastic shotgun shell --all pretty transparent blue polycarbonate, but you still had to use a standard 209 in the rear, and you couldn't crimp them, you had to use top wads with a slight roll crimp.. I reloaded them a couple of times, then kind of let it go, since I had plenty of AAs around anyhow. However, the pressure levels in shotguns is much less (what, around 25,000 "psi"?) than in a modern rifle... but it's close to pistol pressures, so maybe full plastic cartridges are a possibility for handguns. I think the .45ACP standard pressure is around 15,000 "psi," if I recall correctly. And Speer used to make plastic cases for firing plastic practice bullets at low (primer only) pressures.

.45 ACP standard pressure is 21,000 psi, but I think the pressure curves are the biggest difference between pistols and shotguns in this particular application... FWIW, some pistols are quite a bit higher than that. 9mm NATO is running at 42,000 psi max, for instance.

VERY interesting thread.
Wes

 

[Gifted]

Come to think of it, the tround was basically an odd-shaped telescoped cartridge. I was looking at something like that to feed a rail gun, which doesn't have extreme chamber pressures to deal with. Any kind of electric infantry weapon is decades away though. Vehicle weapons? Sure, easy to stash the large generator and capacitor pack needed, but it's not small enough for a soldier to lug around yet.

 

[230RN]

The fumigator:

Thanks for the update on pressures. I was kinda half-guessing, half remembering. I thought it was lower than that for most pistol rounds.


White Horseradish:

How about a diesel gun? Spray oil into chamber, sprung piston compresses mixture, it goes bang, slug goes forth, piston gets recocked for next shot. You could probably run on vegetable oil and market it as a green gun.

I can't document it, but I remember reading somewhere from an authoritative source (not the 'net) that in fact this method has been used in a prototype military weapon. It had a container of fuel which was injected into the cylinder on cocking.

Experienced spring-air-gun shooters know that if you oil up the gun too much, the compression in the cylinder will ignite oil vapors/spray in the compression cylinder just like in a diesel engine, due to adiabatic heating. When this happens, pressures higher than that which the airgun was designed for are generated, and it has a tendency to blow the gun's seals. The phenomenon is actually called "dieseling" among compression pellet gun shooters.

When I over-oil my ancient Feinwerkbau 177 pellet rifle, there is a distinct sharp crack on firing and it blows a little smoke and the room smells lke a diesel bus just went through the house. Time to store it muzzle down for a while to let the excess oil drain. And to thoroughly curse myself.

There was also, for those having interest in various ways of propelling projectiles, a centrifugal machine gun, circa WWI, where large ball bearings were fed into the center of a spinning impeller, and were thrown out at about 1200f/s in the general direction of the target. A large generator set and motor were required. Hatcher's Notebook, page 96, has a photo of this machine along with a few morsels of information on it. It was invented by a person named Moore.

Kinda puts a grin on one's face when one reflects on the definitions of "auto" versus "semitauto." One projectile for each flip of the switch for civilians? Heh.

An awful lot of weird stuff was dreamed up in WWI because of the difficulty of waging trench warfare in those days.

 

[PercyShelley]

Kind of obviates the purpose-- to reduce brass consumption.

Au contraire! A higher pressure brass cased system would use less brass per case for the same reason that .308 uses few raw materials than .30-06 for nearly the same performance.

I can't speak to whether ceramic debris from a piezo ignition system would be more abrasive than what currently exists, although I agree in suspecting that it might be, but I do know that quartz is piezoelectric, and quartz is pretty strong.

Centrifugal force weapons are a silly idea for the simple reason that they cannot be easily rotated against the axis of their rotation. Precession is like that. A weapon with a vertical spoke and a big, horizontally spinning flywheel would be quite difficult to adjust for elevation without the whole affair going wobbly on you.

Oh yeah, and then there's the fact that you need some sort of power source to spin the wheel up in the first place.

Compressed air ignited systems are attractive for two reasons:

1) In making them engineers can leverage over a century's intimate experience with internal combustion engines.

2) Since the deflagration of the propellant will use oxygen from the air, the propellant can be lighter and less bulky.

Now how hard would it be to make a self-loading compressed air ignition system?

 

[ThomasT]

I've thought about this for a while.

What if the firing chamber were filled with a combustable gas? The bullet could seal the front and a metered amount of propellent is introduced into the chamber. The propellent would be fired by a spark like a gas engine. A new bullet fed in to seal the barrel and another metered charge shot in.

Air rifles use a valve system to send the pellet on its way. A similar valve would allow the user to regulate how much propellent was injected.

Cases and primers would be gone. Only a bullet with a seal on its base would be needed. The propellent could be stored in the buttstock like the old air rifles.

That way if there was an explosion you wouldn't be crippled.

You would be dead.

Just kidding. The gas canister could be screwed to to forearm like some of the air rifles have.

 

[bl4ckd0g]

After reading this thread, I'm getting the urge (again) to purchase a stainless Ruger Old Army revolver.

 

[PercyShelley]

I've thought about this for a while.

What if the firing chamber were filled with a combustable gas? The bullet could seal the front and a metered amount of propellent is introduced into the chamber. The propellent would be fired by a spark like a gas engine. A new bullet fed in to seal the barrel and another metered charge shot in.

Air rifles use a valve system to send the pellet on its way. A similar valve would allow the user to regulate how much propellent was injected.

Cases and primers would be gone. Only a bullet with a seal on its base would be needed. The propellent could be stored in the buttstock like the old air rifles.

That way if there was an explosion you wouldn't be crippled.

You would be dead.

Just kidding. The gas canister could be screwed to to forearm like some of the air rifles have.

Fancy, high-end potato cannons work a lot like that.

 

[PAshooter]

I've thought about this for a while.

What if the firing chamber were filled with a combustable gas? The bullet could seal the front and a metered amount of propellent is introduced into the chamber. The propellent would be fired by a spark like a gas engine. A new bullet fed in to seal the barrel and another metered charge shot in.

Air rifles use a valve system to send the pellet on its way. A similar valve would allow the user to regulate how much propellent was injected.

Cases and primers would be gone. Only a bullet with a seal on its base would be needed. The propellent could be stored in the buttstock like the old air rifles.

Both liquids & gasses have been tried, and found impractical. The Crusader self propelled artillery system was originally intended to use a liquid propellant scheme, but it was abandoned. The trouble is, flammable liquids and gasses detonate when ignited, whereas modern smokeless propellants burn. You can't safely generate the velocities demanded of modern small arms (or large ones either, for that matter) without controlled propellent burn rates. That means solid propellant.

 

[PercyShelley]

Internal combustion engines seem to avoid detonation ("knocking") by careful design and fuel selection.