So, I'm playing with the relatively new various Russian slugs that I can now cast, that use a "tail" wad that stays with the slug during it's flight. I am also using some of those, or similar tail wads, in some experimental shells I'm playing with. I have a question about those, and flying them above the speed of sound.
First, let me mention that there is no manufacturer load data for these slugs, so no help there. Most slug load data has them flying at over the speed of sound. However, that might not be feasible when using these wad systems I'm thinking.
These slugs, with their wads that fly with them to the target, are stabilized by the wad. Meant to be shot in smooth bores without rifling to stabilize the slug, they instead use the wad to aerodynamically stabilize things.
But therein lies a problem. At the speed of sound, a shock wave forms off the head of the projectile, and whatever airflow there is around the payload at that point could not be counted on to flow by the wad to aerodynamically stabilize the package. At least those are my thoughts.
So with the above in mind, I'm thinking that these slug/wad together setups would necessarily have to be loaded subsonic if reasonable accuracy is to be expected. Which of course, is the whole point to begin with!!
Another angle might be I suppose, to use a rifled choke to stabilize the wad/slug during the supersonic portion of flight, with aerodynamic stabilizing taking over via the tail wad, when the whole mess drops subsonic.
The idea here is being able to use a smooth bore to shoot slugs accurately, when you don't have and can't get a rifled barrel.
Comments, thoughts, and ideas/theories highly welcome.
Vettepilot