With hybrid slugs you don’t need superior heavy, they actually prefer a little slower twist rate because their donut like hollow core exaggerate the gyroscopic effect or rotational torque of the hybrid slug and becomes more stable compared to the solid core/normal slugs at the same rotational speed.
the difference between dish and flat based slugs to my knowledge is relatively minimum. Generally it affects the aero dynamic of the slug and because lack of material at the base of the dish based slugs it makes the dish based slugs are slightly longer and shift the center of mass ever so slightly forward but the difference is very small. The problem with most airgun pellet barrel is the twist rate is low and the slugs are shot with very barely enough gyroscopic stabilization that any length increase could push it over to be not stabilized but easy fix is a slug specific barrel which will have more than enough twist rate to stabilize the slugs properly then there is no difference besides VERY small aero dynamic difference that most likely will not show up in the published BC.
In summary with normal solid core a lugs or slugs besides FX Hybrids you need a dedicated slug barrel to shoot them well reliably, very little guessing involved. Not saying some of them won’t shoot well out of normal airgun pellet barrels, just the chances will be lower and you need to do a lot more testing. With FX superior heavy liners I have not found a slug that wont’t shoot well in them yet.
