Driving Band
A raised band on some solid bullets that engages the rifling while reducing bearing contact and the fouling that comes with it.
A driving band is a slightly raised ring machined onto the shank of certain solid bullets, sized to engage the rifling while the grooves between bands ride clear of the bore. By concentrating contact at these narrow bands, the design shrinks the total bearing surface that drags against the lands.
This approach is most common on a monolithic bullet turned from solid copper or a copper alloy, where full-length contact would otherwise build pressure and leave heavy fouling. The relieved grooves give the displaced metal somewhere to go, which can lower friction and help a long solid bullet shoot cleanly without spiking chamber pressure.