Grease groove in WWII .303 bullets important or not ?
I use to salvage bullets from (corrosive primed/cordite loaded) WWII ammo before handloading them with modern primers and powder. However, I tumble pulled bullets prior to handloading until they come out shiny. However, I've noticed that the original bullets carry a grease groove which is also cleaned out during tumbling ; then, after being sorted in weight lots, they shoot quite accurately on top of N140/40.0, though. Am I wrong in tumbling the bullets and should I preserve the greased groove ?
https://www.milsurps.com/images/impo.../wamvgaT-1.jpg