Rifled Sabot

[XxLT250RxX]

Pretty much finished with my cannon (pic soon) and starting to think about a mold for the projectile.  The barrel is 1.25 bore plus correct windage.  It is made of steel, meets the one caliber rule and is smooth bore.  The projectile below will weigh approximately the same as a cast 1.25 lead ball.  When assembled it will be 2.5 inches long. 

Do you think it will actually spin in flight?

Would you permanently fasten the wood/plastic sabot to the lead slug or does it need to separate when leaving the muzzle?

[GGaskill]

I think if the fins were on the sabot, it would be more likely to spin.  The "rifled" slugs commonly sold commercially for shotguns are kind of like that and I have read that they do not spin or spin very slowly.  The large hollow base is what keeps them flying nose forward.  Your tail should do the same.  I would permanently connect them.

I am assuming that the tail piece from the front will be completely inside the sabot.  If not, I think that it will buckle from the firing forces.  Maybe use a piece of 1/2" conduit instead.

[XxLT250RxX]

I am assuming that the tail piece from the front will be completely inside the sabot.

You are correct, tail does go inside the sabot.  The sabot has a hole through the center.  I don't see how it can buckle.  Click to see the large view.

[RocklockI]

I'd forget the "self rifling" projectile because none I know of has ever worked . I designed a few but I dont think they'd work either .

Go "finned 120mm smoothbore" idea ,or finned mortar shell profile .

It's been my understanding for many years that the "Foster Slug" is only nose foward because of the wieght foward thing not the ribs on the side .

Basicly ditto of above .

[Terry C.]

There is a less-than-lethal shotgun round that uses a hard rubber projectile that resembles a blimp. Fat in front, tapered toward the rear, with fins.

It doesn't spin, but from what I can gather, it's pretty stable in flight.

Of course, being a lightweight projectile the effective range is very short. How it would perform cast in lead at longer ranges is unknown. It would probably need to be slimmed down and possibly cast with a hollow nose to keep the weight down.



My ¼-scale Napoleon also uses 1.125" projectiles. I cast my own lead round balls, and am currently experimenting with scaled-down canister.

Something that's still in the "dream stage" is a finned stabilizer that would screw into for one of my cast balls. Making the finned shaft would be easy enough, the hard part would be the discarding sabot required to launch such a projectile.

If you did come up with something that worked, I would be interested in seeing the results.

[GGaskill]

I don't see how it can buckle.

It can't if it is inside the sabot.  My first understanding of the drawing was that the pieces would be separated when fired but I ultimately decided that was not the plan.  As I said, I would permanently attach the sabot so it acts like a tail.

[cannonmn]

I'm just putting these pix here because they are somewhat related to the discusson.  It shows some inert 30MM discarding sabot rounds we had a while back.  The penetrator was tungsten, sabot petals were aluminum or some similar alloy.  These were for rifled cannons of course.  The whole round was about a foot long and the tungsten penetrator alone was about 6 inches in length.  The diameter of the white obturating band was a bit over 30mm.

[Victor3]

 Years ago I made up some of these to shoot out of a flare gun. A long firing pin extension punched the CO2 seal through the tube, which shot it out of a long bbl insert. They seemed to fly pretty straight, but I didn't do any real accuracy testing. No sabot was used.



 For yours, you could add four fins to the tail, cut the sabot into equal pieces on a band saw and add a disk behind the sectioned pieces that would butt up against the end of the tail. Tail would have to be light, and sturdy enough so it wouldn't crumple upon firing. You'd want to design the sectioned parts so that the pieces would strip off reliably.

 This design would probably be best for use with very light charges.