Info Needed 32-40 Headspace Dimensions

[Kmrere42]

Hi,





Looking for the go / no go dimensions for the head space gauges.  They are the same for the 30-30 winchester. I am starting a new project and will be needing to make up a set.



Thank you,



Paul

[trotterlg]

Because it head spaces on the rim all you need to know is how deep to cut the rim.  The SAAMI spec is .063 rim thickness, but all brass I have ever measured is .006 to .008 less than that maximum.  If you cut it to maximum you will end up with near excess head space. I have done a bunch of rimmed H&R stubs and rechambers and have found this to be true on every one I have done.  Just use a depth gauge on the rim when you cut the chamber and never go to the SAAMI max, I cut mine at least .005 less.  Good luck.  Larry

[wtroger]

On Rimmed cases I cut the chamber only deep enough for the go gauge to close. i actually like to feel it touch at the very last of the action closing. On h&r's I cut only deep enough to get a solid lock up. And I never want to see an action even attempt to close on nogo gauge. the closer to zero headspace you can get the longer your brass will last and typically the better they will shoot. My way of doing it not necessarily the way others do it.

[Frank46]

I second what the other two gentlemen have said. i measured the rim thickness of about 100 30-30 cases all were below the sammi minimun for that case. This was for a Ruger#3 that was to be strictly a cast bullet fifle. I sent some cases which had identical rim thickness measurements to the smith. About a year later I get the rifle and after inspecting his work thought the recess for the rim was too deep. It was. So now when I fire it the primers protrude .007-.008 from the case.I had written specific instructions on how the rifle was to be headspaced. He was to push the breech block as far back as he could get it add .001.5 so that the block was almost rubbing the breech face of the bbl. And still the primers protrude the same. Sort want to make me take up drinking as a second hobby. Frank