Minimum Headspace?


Doug S
September 3, 2004, 05:33 PM
I recently posted about a head space gauge I purchased for my Mosin Nagant carbines. I went with the No-Go gauge because it seemed the best for general purpose use, & of the type most likely needed for problems. Now I'm wondering if I should get the Go gauge which measures minimum headspace. Is it possible to have a minimum headspace problem & still get a bolt closed? I do have a M44 whose bolt is hard to close bolt when loading a round. Once the extractor pops over the rim, the round is quite easy to chamber and close the bolt. So, I'm thinking this is an extractor issue, but still I wonder if I should check the minimum headspace. The rifle passed the No-Go gauge without a problem, but this measures maximum space, not minimum. From what I've read surfing around the net, it seems that if a rifle really has too little headspace that the bolt will not go closed. Is this true, or could this bolt issue be the result of too little headspace? If so, is it potentially dangerous. I had the rifle to the range once, & the fired cases looked okay to me. Can someone explain minimum headspace issues to me? Thanks, Doug

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September 3, 2004, 06:38 PM
Not familiar with that particular rifle, but it sounds like the extractor is creating your effort and not an undersized chamber. Generally, if the bolt closes, you're good to go from the standpoint of minimum headspace.


Doug S
September 3, 2004, 07:21 PM
Thanks for the response. I'm leaning toward it being the extractor also, but wanted to get feedback from others on this issue (especially if minimal headspace could be dangerous).

Doug S
September 3, 2004, 07:27 PM

September 3, 2004, 09:12 PM
Headspace guages don't actually measure anything. They only tell you if the rifle/bolt combination is within spec. It's highly unlikely you have low headspace on a surplus rifle. The barrel would have to have been removed and put back on too far. A No-Go and a Field are sufficient. The Field guage is the test for maximum headspace. If a bolt will close on a No-Go, but not on a Field, the head space is high, but still within spec.
"...Once the extractor pops over the rim..." Are you chambering a round and closing the bolt? That'll cause your problem. The case head should come out of the mag and its rim should slide under the extractor. The extractor should not "pop" at all. Load through the mag and your problem will likely go away.

Doug S
September 3, 2004, 10:57 PM
Sunray, thanks for the info. Actually "pop" is a poor description. I do load the rifle through the magazine. When I proceed to chamber a round the bolt will close, but it requires significant force. Not really extreme effort, but not easily either. When I say the extractor "pops" over the rim, what I should have said is that once the round is chambered (but not fired) if I then open the bolt and start to extract the live round (but stop just before the point of extraction), I can then rechamber the round and close the bolt repeatedly with little effort. Following the initial chambering I can see that the extractor is now over the rim of the round. This had made me wonder if the extractor is too tight, or not yet broken in from the time it was refurbed. I hope this better explains my hard to close bolt.

Actually the word "pop" better describes the sound that the bolt handle makes as I push it down & to the right. The bolt requires enough force to close it that it "pops" over the corner of the metal at the top of the receiver where it enters the slot & sits when closed. Tell me if this doesn't make sense & I'll try again.

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