Say something along the lines of depleted uranium. Maybe a nylon jacket or sabot. Say a 30 or 338 cal slug shaped like the Devel (muzzle loader) bullet (handloader #210 page 72) that has a polycarbonate tip.
A nonexpanding hunting bullet that has a high ballistic coefficient and can probably irradiate your meat for you all at the same time. [img]images/icons/grin.gif[/img]
If I see this bullet in the near future come out under the Lost River Ball Tech new products. I expect to see some royalties. [img]images/icons/grin.gif[/img] [img]images/icons/grin.gif[/img] [img]images/icons/grin.gif[/img]
An 80 grain bullet weighs 80 grains. It does not matter how dense the material is. It will occupy less volume, but then you won't be able to optimize the front end. Remember there is a rule in bullet making. The OAL of the bearing surface(the shank) has to be at least as long as the bullet is wide, so that it doesn't try to get sideways in the bore. A .308" cylinder that is .308" long has a volume of .0229 cu. in. Uranium has a density of .676 lb/ cu. in. The shank would weigh 108.59 gr. You could do some type of wasp waste to reduce the volume and keep the shank OAL the same but it would screw up the aeros and reduce the BC. Area Rule works in supersonic jet fighters but is worthless in bullets. They do not have wings.
I have experience with poly materials. When you use them as the leading edge at Mach 3+ velocities they begin to change shape after about .5 seconds flight time. The temperature builds to above 500 deg. F. at the leading edge, dependent on the tip shape, and combined with the tremendous back pressure it is sufficient for even the most high temperature resistant poly materials to begin to flow. The result is at that point the BC begins to decline.
The only way that I can see to get a 1.0 BC with a 30 cal. 80 gr. bullet would be to add thrust in flight. If you machined a combusition chamber into the rear half of the bullet and a very precise nozzle, then filled this with solid propellant, maybe you could get enough thrust to get the equivalent of a 1.0 BC trajectory. But with this configuration you can forget anything like what we would call accuracy. The ignition delay parameters and the burn rates would not be nearly precise enough. You can get much better control with liquid propellants but that requires pumps and regulators. Besides that, all this fuel and stuff is extra weight.
If you use a sabot and subcaliber the 80 grain projectile you can do it. If it is spin stabilized it will only be as accurate as the shoe material will allow, which is generally not great accuracy. It is more accurate to fin stabilize a subcaliber round, but you need a very high sectional density, >.600, to overcome the drag the fins add. Also, you need a smooth bore.
The point I am meandering around is that it is tough to repeal the laws of math and phyics.
Warren, I'm afraid you bringing these physical realities to light has burst a lot of bubbles. [img]images/icons/frown.gif[/img] [img]images/icons/frown.gif[/img]
I was absolutely certain we could come up with the 'magic' bullet. [img]images/icons/grin.gif[/img] [img]images/icons/grin.gif[/img]
Again, thanks for spending the time and effort to post these replies and the fortitude to put up with our sophmoric ballistics designs. I truly enjoy the posts and am greatful for the opportunity to have knowledgable folks to query. Thanks!!
One last item. Are you sure about the laws of physics? How about if we tried using the burnt stuff off the bottom of my wifes cookies as a sort of heat shield, could we get a hollow polycarbonate bullet to fly and not melt. (That burnt stuff is really heat resistant, those cookies are still RAW in the middle!) [img]images/icons/wink.gif[/img]
Burned cookies as a heat shield! You might be on to something there Dave. [img]images/icons/grin.gif[/img] [img]images/icons/grin.gif[/img]
Actualy I was thinking of some thing along the lines of a bullet that has the aproximate shape of the heavy Sierra Match Kings in 30 and 33 cal. Maybe replace the polycarbonate tip with a hollow thin copper or aluminum tip. But mantain a flat front under the more aerodynamic sharply pointed tip. Something to give you at least a one caliber flat front surface. Keep the weight about even with the match kings, 220-250 for the 30 and 250-300 for the 338, or even higher if need be. You wouldn't get super high velocity but the BC would be awesome!