I only ever use my HW30S for Bell Target and 10m paper and have never considered the couple of thou discrepancy that mixing these rail, block and sight combos raise to be a real issue.
Certainly not at my skill/accuracy level anyway.
And, if it's any further help, there's some pics and dimensions here -
And... the link doesn't work. Looks like something here is stopping it from pasting in full because it comes from another forum.
Oh well...