I usually get off work about now, so it's the perfect time to take a pot shot at my favorite cannon gooroos. 
Ahhh... so them were you two in the back of the conference room, measuring the water cooler bottle for some strange reason ("Hey Mike, ya think they'll ever make these out of plastic?"). I knew we had met, and your "magic bullet" theory is makin' more sense to me now. 
All joking aside, thanks for your reasoned 'splaination of how you determined what happened with your bolts.
Still though..... 90% of the mass up front, drag stabilized via nothing more than that little band/pocket at the rear? :-\
Ah, so that's how you can zing us with such regularity! We both worked those hours in the mid 80s for Sundstrand Aviation in North Denver. You learned to stay awake there in order to stay alive. THAT was a REAL FACTORY! They had a couple hundred thousand 2 X 4 wooden blocks about 4" long on end as a floor surface. They were so loaded with cutting oil and black filth in our area, (precision grinding), that if you ever fell and landed on that floor, you needed to pitch your clothes in the dumpster at the end of your shift and drive home in your underwear!! That oily, black slime would never come out!
About your last sentence, we both agree with you there and don't think that little void would do the stabilization trick reliably. GGaskill posted a pic of his 30mm minie-type slug recently and we like the looks of it much more than our "lightweight bolt". Just maybe a composite projectile could provide the best of both worlds, first a heavy, cast-lead, ballistic nose and, second a tough, thin, smooth, steel lower part which could be close to bore size, but would not expand and yet be light enough to be very sensitive to air pressure, just as a lightly constructed weather vane is. I'll work up a sketch or two and post as a mod later.
Tim, we are glad to hear you are getting back into the shop. Who knows, we could really come up with something really accurate if our members don't hold those slightly wild ideas back. Keep going Tim, we know you have a gold-mine of raw material in your shop.
Yes, we will be going back to the northern plains to make more discoveries, but we will be there more often to add artifacts to the landscape. Gary, I think all the heavy powder charge bolts I shot in 2005 are lying on the slope of the 120 foot tall, final backstop hill which we saw last time out at around 3,100 to 3,300 yards, almost the 2 mile mark. Are you up for another hike?
Regards,
Mike and Tracy
P.S. Thanks for the tip DD, but our good friend Bruce has 3 or 4 and goes out gold and artifact hunting all the time. We just went out with him to try some new loads in his 45-70 and a 300 win. mag so maybe we could try to see if there are any bolts hiding under those large cactus patches out there. Good idea.
