Mosin bolt headspace question for the experts

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Minuteman
Oct 11, 2013
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Looking for another donor bolt for my 91/30. I'm wondering how the headspace/bolt assembly works on this thing. I know it's rimmed so the casing headspaces off of that, but on the bolt head itself, what's allowing that to happen? Is it the bolt face itself that's sunken in those few extra thousandths where that variance happens? And if I find another bolt, can I just yank that head off and install mine and have a good to go headspaced setup again, or is there something behind the bolt head that also affects all of this.

Thanks for your help.
 
It only headspaces in association with the bolt head. You can swap your original one onto another body/handle. Headspace on rimmed cartridges is measured from breech face to the face of the bolt. As an aside, if you have one out of spec you can try different bolt heads to correct headspace.
 
So it does work as I was thinking, which is all I'd have to do is buy a bunch of bolt heads and find the one that works as far as correcting headspace, and conversely, doing the opposite is fine if I wanted to switch out bolt bodies to a bent bolt?
 
They are not #'ed like Enfields. Bolt heads are getting hard to find and very expensive. I have never seen a Mosin that had bad head space. But a deep shoulder is another thing all together just like a 303 is.
 
The really nice condition Ishevsk numbers matching 91/30 I have will barely close on a go gage. I forced it down once but dont want to do it again. Have a spare bolt here and changed the heads and it seems a little better with these go and no go gauges.