File:Schenkl projectile.jpg

Summary
Figures 261 and 262 from A Treatise on Ordnance and Armor, by Alexander Lyman Holley, published 1865 by Trübner & Company (digitized by Google books). This illustrates the Schenkl projectile, a streamlined shell used by Union forces in the Civil War. The shell had a grooved, truncated cone at the rear, which was fitted with a papier-mâché sabot, which was forced forward by firing, expanding as it slid up the cone, engaging the rifling and sealing the bore. The grooves in the cone lock the cone in place to the shell, transmitting the rotation of the rifling to the shell. The sabot disintegrates upon exiting the barrel.