Abstract: A saboted projectile comprises a sub-caliber, spin-stabilized warhead (usually an armor-piercing penetrator) and a full caliber spin-stabilized non-disintegrating sabot capable of being fired by airplanes. The sabot releasably receives the armor-piercing penetrator and is adapted to be mounted on a conventional ammunition cartridge. The sabot includes a novel method of holding the penetrator until firing, tightening a reverse threaded end cap against the aft end of the penetrator during firing and utilizing interior end cap geometry to utilize firing gas pressure to accelerate the penetrator forward in relation to the sabot after leaving the gun barrel. Accuracy is increased by maintaining axial symmetry and releasing the penetrator in substantially the same way each time. There are other novel features.