taking the idea "shoulder cannon" a bit too literally :)

[WheelMan]

my apologies if this has been covered a quick search didn't turn anything up.

First of all let me qualify all of the following by saying that this is just a musing, I'm not trying to argue for the need of or even usefulness of what I'm about to present, but am mearly exploring some ideas with people who have knowledge of the subject.

The question about flechettes got me thinking about shotgun loads other than shot and slugs. and if there was really anthing else that have even remote utility.

It occured to me that a modern smoothbore main tank gun is in many ways a big shotgun. This made me wonder if the technology used in modern kenitic tank rounds could be scaled down to shotguns. Obviously this would basicaly turn the shotgun (poorly) in to a rifle. That is: one, small and fast projectile.

First a question for the aerospace engineers, there are aerospace engineers aren't there? Can the shape that stabilizes a fin stabalized saboted tank round be scaled down succesfully to a size that would fit a shotgun... say a projectile weighing 100-200 grains. taking into consideration it would have to be made of something lest dense than DU.

And for the reloaders.. could a 12 gauge shell pack enough powder to send such a projectile at an appriciable velocity (say 2000-3000 fps ish depending on weight)? If not what kind of overpressure would be required?

Obviously this could do nothing that wouldn't be better accomplished by a rifle, shotguns sights are generally not appropriate for this sort of thing nor is a 12 gauge shell an efficent way to carry around such a small projectile, but as I said, I'm simply musing. In short, can a tank cannon KE round be scaled down to 12 gauge.

Moderators, is this is more appropraite to the reloding forum go ahead and move it, I wasn't quite sure where it belonged.

 

[Dave McCracken]

It's been done, sort of.

Cannon ammo was the inspiration for the sabot alugs so common these days.

The limiting factor here is pressure. Velocity requires preessure, greater velocity greater pressure, all else equal.

Cannon,IIRC, operate at up to 75K PSI. Top pressures for shotguns are 13K.

IMO, a situation requiring a 2000-3000 PSI projectile needs a rifle.

 

[themic]

remember also that stabilizers require length and extra velocity to spare... they will slow it down a bit. in rough terms, energy's gotta be conserved, and the stabilizing force (essentially drag) will be taken out of velocity.

 

[Preacherman]

It has indeed been done... In France, one of the ammo. designers for their tanks' main cannon turned his energies to designing shotgun slugs. The result (named for him) is, IIRC, the "Sauvestre" slug. They can be bought here from a few suppliers. They are apparently classified as a munition of war in France, because they penetrate so well!

Does anyone have any further info. on these? Perhaps a Web search might be useful.

 

[Brad Johnson]

The sabot rounds in the 120mm smoothbore gun on the Abrams are much smaller than the bore. If memory serves, the anti-tank projectile is a tungsten dart somewhere in the 30-40mm range. Scaled down to fit a .30 cal rifle, this would mean the projectile would end up being about .075-.099 cal.

The muzzle velocity of the 120mm sabot round is well in excess of 4000 fps - a result of the relative light weight of the projectile to bore size. The same result is achieved in the Accelerator sabot rounds you can buy for a .30-30 and .30-06 (4100 fps). Any faster than this in a spin-stabilized round and centrifugal forces can cause the projectile to vaporize as soon as it leaves confines of the the barrel. Those of you who regularly shoot hot-loaded .220 Swift will be able to relate - the gun goes bang but there is a black puff in front of the gun and all you get on the target is a dark smudge.

Even though the light projectile would allow high muzzle energy due to huge velocity increases, it would also result in high velocity losses to aerodynamic drag and an extreme susceptability to crosswind-induced deviation. This alone would probably negate the ability to use it as an effective long-distance game getter.

There is also the problem of friction heating on the thin, pointed surfaced of the stabilizing fins. 4100 fps is 2795 mph (roughly mach 3.7) At that speed friction-induced heat is incredible and would almost instantly vaporize the leading edges on the tiny stabilizing fins on a .10 cal-or-smaller dart, rendering them ineffective.

Brad

 

[9x19mm]

Here you go:

http://www.sauvestre.com/index_us.htm