[Oleg Volk]

Would a slug with a "H" cross-section fly reasonably straight from a smoothbore?

[Fred Fuller]

Oleg,

Sorry I'm slow, but I'm not getting the point to making a shotgun slug with an H cross section. If the channels in the slug body were 'swirled' or twisted then there might possibly be enough air resistance generated to impart enough spin to help stabilize it. And it might be that there would be enough air resistance generated by the profile itself to keep it from tumbling, I don't know. It would depend on laminar air flow and a bunch of stuff I'm too ignorant about to even bring up. I am told that the 'rifled' marks on standard Foster type slugs actually do not cause spin either in the bore or in the air- that stability is provided by the nose- heavy, hollow base design of the slug.

I remember the introduction of the BRI (Ballistic Reasearch Inc) wasp-waisted slug several decades ago- it was a sabot slug which also had a weight-forward design, but shot fairly poorly out of a smoothbore. It was really impressive out of a rifled barrel though. Some were made of really hard alloy in the early days (back in the 1970's) and would penetrate like nobody's business. The basic design is still loaded by Winchester IIRC, but the projectiles are now of a much softer lead alloy for expansion.

The other fairly unique approach to slug stability in flight is that of Brenneke. The original Brennekes used a thick felt wad that was literally screwed to the base of the cylindrical lead slug with a wood screw. The walls of the slug are still scored with 'rifling' but that is to allow the slug to pass through shotgun chokes with no trouble. The more recently designed Brenneke/Kent KO slug is similar but has a plastic wad, the 'nose' of which fits into a hollow in the base of the slug. It is retained by being 'staked' in several places through the sidewall of the slug. The wads essentially act like the fletching on an arrow, keeping the projectile oriented in flight. Both these designs have given excellent results for me through the years, Brenneke slugs are made of a hard lead alloy with sharp shoulders that make cookie-cutter like holes and penetrate deeply. The KOs are very economical to shoot as well.

The down side to doing anything to a shotgun slug that changes its shape from cylindrical is that it costs in weight of the projectile. If the intent is a corresponding increase in velocity without a measurable increase in recoil, there might be some benefit there. Higher velocity gives flatter trajectory, and the popular sabot designs tend to give up a lot of weight relative to the basic Foster type slug in seeking a flatter trajectory with manageable recoil. Us old stuck-in-the-muds LIKE heavy slugs (well, one ounce anyway), those modren fellas with rifled shotgun barrels tend to go for the sabotted stuff.

Hope this ramble helps,

lpl/nc (still shooting smoothbores)

[sm]

Lee,
Nice write up, especially the importance of stability of wad being akin to fletching.

I do know cutting an "X" in 'em don't help, and filling that hollow point with silicon, Pla-Doh and such reduces accuracy. I found "sometimes" making the base more "hollow" aided in accuracy. Just have to be careful reloading a factory Foster slug. . I did have some .410s that I "hollowed out more" and left some very sharp edges that improved the accuracy.

[I]Paging Preacherman... He had link(s) with the history of slugs with pictures. Very interesting to read and see various developments over the years.

[mrmeval]

Do you mean shaped like Darth Vader's fighter? It would need a good gas seal and probably an attached wad that helps stabilization. Making the Xwing version would be tougher.

Don't do a stack of dimes, some will come back at you. :)

These however rock! 1.2 ounces looks like a beeman air rifle pellet all grow'd up.
http://www.outdoorsuperstore.com/store/hunting/productDisplay~manufacturer~LYMAN~model~SABOT+SLUG+MOULD.htm

Would a slug with a "H" cross-section fly reasonably straight from a smoothbore?