Richard J Kinch wrote:

I'm wondering if you couldn't turn the ram smaller, epoxy on Teflon or
Turcite sheet, and turn that to the original bore size. That's how flat

I've never used Turcite so can't comment on that but I've done lots with
Teflon. Teflon will cold flow so doesn't work well anywhere significant
pressure is involved. UHMW polyethylene would be much better in this
application.

Ted