Originally Posted by Nimrodmar10
If the ram is square or not, which I'm sure it probably is, doesn't really matter. When you set your dies to bump the shell holder on the top of the stroke, it squares the die with the shell holder, which squares the case also. There's probably more slop in the fit of the shell holder into the top of the ram than there is between the ram and the frame. If you didn't have some clearance you wouldn't be able to get a shell holder in and out.
One press has guide rods to maintan alignment, and the other dose not. It's quite common to see the bore for the ram wear out of round and also with a taper in it. I've rebuilt a couple RCBS presses in the past and the bore wear will often be scarey. A before and after check in a shadowgraph proved these issues, but you can also see them with a NECO case gauge.. I reground one ram and hard chromed the other and reground it. Then made bushings to sleeve the bore. One was with Ampco bronze and the other was with steel drill bushings. Set the presses up for .001" clearence (maybe .0015" as it's been awhile). Made a world of difference.
On the otherhand the Co-Ax press I own was bought before Forster owned the company (1978), and it's just as tight and square today as the day it was unboxed. This has tobe from the guide rods that controll the ram's travel