Well, nobody has commented yet, so with the understanding I know NOTHING about punching eyes thru a hammer I'll ask a couple of questions. I think I remember you having the Coal Iron press that's advertised as 12 ton? It has a 3" cylinder? If so, I've been impressed how well 9 ton works.
How much clearance do you need between top of stripper and the bottom of punch die base once the press is all the way down? I've never tried to punch a hole thru anything thick like a hammer. Seems like there should be a hole in the bottom for the punched metal to come out, but there's not. I'm guessing the metal is "spread" rather than "punched" out.
Be sure you keep us updated on this thread.
Ken H>