Thread: Headspace gauge/ case head separation

I have had some issues with my 223 case head separation. I split one in half yesterday with the case stuck in the chamber on my first shot on a mob of goats. Luckily the case fell out of the chamber easy enough.
After reading why it's happening (thanks to a previous thread and real knowledgeable fellas on here) I am over working the brass. I have decided I need a headspace comparator gauge so I can accurately bump the shoulder back.
Has anyone used this before from TradeMe?
https://www.trademe.co.nz/4923839449
Are headspace gauges much the muchness? I'm not looking for extreme precision.
Can I bump the shoulder back the 2-4thou with a Lee full length sizing die or do you need a bushings die?