If you knew the PH was 20ga only, then why the discussion of 12ga round balls, eh?

An overstabilized bullet will shoot anywhere from excellent to good, its the understabilized bullets that give real trouble. There will be no stripping with either sabots or hardened lead projectiles, or even reasonably heavy soft lead bullets, at any velocity the PH can reasonably muster. Try this for an excellent assessment of overstabilization, "Over-stabilization as a result of a too-fast twist rate can occur, resulting in a bullet that travels along its downward arc with its tip pointing skyward, exacerbating wind drift and hastening velocity loss. Ideally, the tip of a properly stabilized bullet should tip downward as the bullet begins its downward arc. Clearly, an over-stabilized bullet is not conducive to accuracy, but it is only noticeable in extreme cases of over-stabilization and at very long range. You'd never notice it at hunting distances."

I'll repeat the important part, "...it is only noticable in extreme cases and at very long range. You'd never notice it at hunting distances."

I'll add that as bullet length increases, so does the need for twist. Since some of these bullets weigh close to 1.5 times or so what a round ball would weighs and have hollow bases, making them that much longer, I'm not too sure that the heavier full groove diameter bullets would be much over stabilized at all. (But can't find length dimensions on any of them.)

BTW, if your demands for accuracy are so great, just how is it that you can live with the built in deltas in pressure and velocity inherent in any black powder rifle?

As ussual, all wind.

JPK