head spacing a rimmed cartridge in a bolt action

[mitchell]

when rebarreling a rimmed cartridge (45-70 in my case) how do you head space it . is it just like with a rimless cartridge with a go and nogo ?

[trotterlg]

The breach end of the Nagant barrel has a cut in it to clear the extractor, the rim seats on about half of the diameter of the face of the chamber.  Probably don't need gauges, just set the barrel up until there is the rim thickness between the bolt head face are the rear of the barrel, with it properly tightened down, mark where to cut back the chamber end for the extractor, then just cut the chamber in until the chamber reamer rim cutter just touches the breach end and things will be good.  Larry

[torpedoman]

being cheap i just build a tape stack on the back of the round until it make the bolt stiff then check the thickness with my calipers. reading is headspace.

[trotterlg]

The best most reliable way I have found to find the real headspace of your rifle is to chamber an empty primed case and fire it.  The primer will force the case forward and the primer back against the bolt head, measure how high the primer stands over the case head and you will have the real headspace.  Tape is good too.  Larry