Thanks xausa, I want to have the excessive runout reduced, so will use all methods I can to achieve that. The majority of rounds with the RN bullet exceed .004" but not .005". In my view that's too much and will not aid accuracy.

I have checked the 140gn SST bullet runout & it's much less at .002" so I'm thinking this could be seater stem related, but will check properly tomorrow. It seems to me the stems could be designed for more 'pointy' bullets, so not so great for RN bullets.
But a good look should give me a better idea.

I do already rotate the case/bullet while seating. Some say it helps, others do not agree. I'll continue to do it anyway since it can't be wrong to do so.
Cheers, d