Headspace on a previously installed barrel

[carlsbad]

I picked up a 6mmBR barrel from a guy who decided to move up to 6.5x284. He sold me his barrel, brass, and redfield competition die set. So I've threaded my action onto the barrel for fitup and mearurements so I can order a lug and headspace gauge. It occurred to me that I have fire formed brass from this very chamber. Seems like if I snug up the action on a fireformed piece of brass and then adjust the shoulder to achieve this fitment, it should be perfect. I know it assumes the previous gunsmith did a good job adjusting headspace but the guy seems to be good, the brass looks perfect, and the previous owner reported good success.

What opinions are out there? Would I be better off renting a set of gauges?

thanks in advance,
Jerry

 

[jonbearman]

Get the gages an you will be perfectly safe.Tightening against a fired cartridge could be done but with wide variations as it spings the case as the barrel is being tightened down.Your brass may have been bumped already by the previous owner and if you use the cases as a gage it will be invariably wrong.Rent or spend 60.00 for your own set of gages.

 

[watercam]

+1, better not to cut corners. You can rent gauges from 4-D Products for $8.

 

[carlsbad]

OK. I guess I will get a gauge. Both the rental places turn out to be more than buying a gauge once you pay shipping both ways. Brownells has a gauge in stock. Midway has the lug I need (PTG .2285 thick. ). I guess I can buy an .250 but hate to machine more off the shoulder than needed.

thanks,
Jerry