1. The 75 mm Pzgr . 39 / 42 of sintered iron driving bands . 2. The projectiles used a copper driving band to engage the rifling. 3. The gas-checks evolved into the driving bands still in use today. 4. The manufacture of shell driving bands was another notable contribution. 5. Two copper driving bands provided a gas-tight seal against the gun barrel during firing. 6. This was soon followed by the Vavaseur copper driving band as part of the projectile. 7. The driving band rotated the projectile, centred it in the bore and prevented gas escaping forwards. 8. The wide forward driving band helps keep the bullet aligned as it jumps across the cylinder gap. 9. The double drive wheel is named after its drive band , which goes around the spinning wheel twice. 10. A driving band has to be soft but tough enough to prevent stripping by rotational and engraving stresses.
