I have a RCBS rock chucker supreme press. The ram visually doesn't seem to be aligned with the centre of the hole where the die goes.
After recently buying a decent concentricity gauge I checked the neck runout on some new 6.5 x 284 Lapua brass which was 0.001" - 0.002". I necked up to 7mm using a 21st Century expander die and the runout increased to +0.006"
I also reload .243 Win on the same press and get a fair bit of runout on the necks and bullets using Hornady New Dimension dies. +0.015" bullet runout in some cases.
I know that the dies aren't the best of dies, but with the ram being noticeably off centre I'm thinking that this is most likely the cause of the problem.
Is there a way of adjusting the press or a way to make the shell holder self centre to the die? I'm planning to upgrade to an arbour press and wilson dies in the near future for resizing and bullet seating the .243 and .284, but I want to reduce the amount of runout during the necking up of the 6.5 x 284 brass as it seems excessive.
Any thoughts would be much appreciated. Thanks in advance