Ignoramus5886 fired this volley in
:

Once I get the mill in place, I will put 2x4s under the base.

I should have added... I have a #2 Cincy horizontal mill with a BP "M"
head. It's on roller bars, just because I've never really decided where
it should be.

It doesn't "rock" because the floor is quite level where it sits, but
when I'm using a big out-of-balance tool at a fairly low spindle speed,
the 3200lb machine actually rolls fore-and-back about 1/16". It's not a
problem, but a little disconcerting. You don't so much see it as feel it
when you're on the dials.

LLoyd