Other than holding the bullets secure the amount of neck tension provided by the same sized neck bushing as the fired neck diameter yeilded no difference in accuracy.
Given the solid and repeatable work you were doing without (neck tension), I'm not in the least surprised.
.070 cork wad, gasket material from Felpro punched out on press punch and pushed down on top of veg wad.
Well,....that beats all.
GTC