OK, I'm posting this in the GD because it is one of my goofier ideas.

Could you use the torque of the bullet in the rifling to turn multiple barrels and operate the action in a gatling gun design?  The Beretta Cougars, Colt Model 2000 and other weapons have used rotating barrel actions.  My idea is to attach gears to the barrels and use the torque from the bullets in the barrels to operate a gatling gun action without external power.  I'm not an engineer and frankly have no idea if the bullets could provide enough torque.  Unlocking a handgun's slide is one thing.  Turning several pounds of steel is another.  Still - I thought I'd toss it out there...

I'm not sure I get what you're asking: are you wanting a recoil-operated gatling gun, or are you trying to rotate barrels using the spin of the bullets, which doesn't make sense?

The pressure of the gas released when a round is fired operates most weapon actions.  Regarding the gatling design, they are normally powered by an electric motor, I don't think bullet spin would have nearly enough energy to operate such a mechanism.

Quoted: I'm not sure I get what you're asking: are you wanting a recoil-operated gatling gun, or are you trying to rotate barrels using the spin of the bullets, which doesn't make sense?

The latter, assuming you could still stabilize the bullet by increasing the twist rate.  Presumably rotating barrel action weapons like the Colt Model 2000 and Beretta Cougars have to compensate with a faster twist.

I think what got me thinking about this was reading that the Army is moving away from powered weapons for helicopeters, because they can become inoperable if the aircraft loses power.  IF there is a problem to be solved (I'm not saying there is), a gas or recoil operated heavy barrel, multi-barrel or liquid cooled weapon would probably be better.

Look at the mass involved.....bullet torque is minimal in comparison to the spare gas pressure.

SRM

I doubt the torque of the bullets would be enough unless you had some precision engineering and good ball bearings. Also you would have to figure out some way to store that energy until the bullet had left the barrel, otherwise it would greatly disturb the accuracy.

I'm certainly no engineer, but I think I know why projectiles spin.

They need the rifling to impart the spin, so they aren't even spinning until the barrel MAKES them spin, then you'd have to reverse the process, ie capture the energy you just imparted, or at least the direction you chanelled the energy, back into the barrel.  No way.  Zero sum game at best.

Think about it, even shooting a .50, the torque from imparting the spin isn't perceptable.

A gas system may be a better idea.  Just my 2¢.  

I think it could be possible, just not practical.  

I think what he's asking is whether you could use the torque implied by the rotation of a bolt or bolt head moving after the cartridge has fired and the energy imparted into it has already forced it to move.

I can see where he's going with this. He's asking if one could run some variety of rotary cannon using the power generated by the recoil to spin the entire mechanism, using the mechanical energy provided by the implied torque generated by a locking lug setup.

While the torque implied by each barrel or bolt head is negligible, an accumulation of torque might be enough to actually rotate a collection of barrels around a center spindle point. Observe the diagram I threw together very haphazardly and in a mere few moments:



A. According to Newton's First, and Third Laws of Motion, the force being exerted backward against the barrel is equal to the force of the lead being expelled from the barrel. That equates to a backwards pressure which acts against B.

B. A set of locking lugs set into a helical channel of some variety. These locking lugs force the barrel to twist as it recoils, imparting a small amount of torque into whatever armature that is suspending the barrel mechanism.

C. As each barrel is fired, it twists on its own, imparting a small amount of torque to the main spindle.

D. Cumulitive torque moves a spindle composed of individually-spinning barrels. If the spindle spins, and mechanical doodaddery behind the spindle loads and fires each individual chamber, what you'd have is a device that would spin faster and faster just so long as ammunition is fed to it,


I can see where he's going and if my explanation follows the original poster's description, I can explain exactly WHY it wouldn't work.

1. a freely-spinning barrel wouldn't work, mechanically. There would be no channels for the lugs to react against, therefore the individual barrels would recoil straight backwards, rather than rotating. So, for there to be any rotation in the system, the barrels would have to ride in channels representing a helix shape.

2. If said barrels were loaded into a helical-shaped channel and reciprocated within this channel, they would require springs or some other variety of piston to push the barrels back forward, running them in reverse against the direction they just so recently recoiled. This leads to a negative expression of torque. +1 - -1 = 0. Unfortunately, by adding springs, you've negated any torque that you would have created.

Therefore, based on my understanding of the OP's query, a torque-powered gatling system cannot work.


But! There is good news! If one were to replace the locking lugs with a ratchet mechanism, one could easily capture the mechanical energy inherent in a reciprocating bolt, transfer that to rotational force via a clever set of ratcheting planetary gears and therefore utilize the force of the expelled lead to spin a gatling system, rather than relying on an outside force or gas system to keep it running.

Keep in mind, the above paragraph was wholly educated speculation and is quite possibly not feasable. Your Mileage May Vary.

Quoted: OK, I'm posting this in the GD because it is one of my goofier ideas. Could you use the torque of the bullet in the rifling to turn multiple barrels and operate the action in a gatling gun design?  The Beretta Cougars, Colt Model 2000 and other weapons have used rotating barrel actions.  My idea is to attach gears to the barrels and use the torque from the bullets in the barrels to operate a gatling gun action without external power.  I'm not an engineer and frankly have no idea if the bullets could provide enough torque.  Unlocking a handgun's slide is one thing.  Turning several pounds of steel is another.  Still - I thought I'd toss it out there...

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That would be construed as a machinegun. If it fires more than one round for each pull of the trigger or doesn't have a hand operated crank, its a machinegun, using the forces of the preceeding rounds to operate the gun.

If you have to pull the trigger each time, you have a revolver.......why reinvent the wheel?

Yes.  It would be a machine gun.