Lets see now -- KE (ft lbs) = (W * Vē) / 450436. That gives us (65,870 * 5480 * 5480) / 450436 which boils down to (hold on to your hats!) 4,391,500 foot pounds (that's right 4.3 MILLION ft lbs). Sectional Density = W (in pounds)/Dē. That gives us 9.41 / .6 * .6 which equals 8.4. (That's eight point four--and you thought your 220gr .30 cal bullet had high sectional density at .343 (that's "point" 343.) The newer M829A2 round throws a 10.85 pound , .8" dart at 5512 f/s. I'll leave it to you to figure out the details.

As an interesting side note, when fired at 55 degree elevation, it will travel 113,111 meters (123,630 yards or roughly 70 miles) and reach a height of 44,073 meters (48,171 yards or almost 27 miles). You are NOT safe if someone aims one of these at you. The accuracy of the dart is sub-MOA and the stated effective range is about 3000 meters (3270 yards). However, first round killing hits have been obtained out to about 6000 meters (6540 yards).

Sharp-eyed readers may note the 55 degree elevation for the maximum rage of this projectile. While spin stabilized cylindrical projectiles reach their maximum range in air at angles of between 25 and 35 degrees (45 degrees in a vacuum) the "dart is fin stabilized and not spun (the 120 mm gun is a smooth bore) and this gives it its maximum range at 55 degrees elevation--the fins keeping it point first through out its trajectory and providing some lift.