Clide, completely reworking and putting in linkages etc. may be the next step, but you sure took a H***uva first step.

I'm doing mindwork on a smaller steel version of the HEAR valve.
I like the o-rings, but in need of a lathe, I am going in the direction of more flappy valving. Something ...

Sorry to state this, but I think you have a couple of concepts confused (well, to some point).

Stability (1) is just a question of keeping the orientation of the projectile at impact as it was on firing. Front end first, duhh ;)

Stability (2) is a question of having the projetile going the way we ...

Sorry to kick open an old topic, but I actually have something new for you, Clide.

First, I'd like to congratulate you for coming up with this er... contraption.
Did you think the HEAR valve up yourself? (Yes or no will do, I didn't search for it, so flame me at my peril :P )
It was just what I was ...