Lee enfield headspace problem

hardek

hardek

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Hello, I just bought a no.1mk.3 sporter. I checked the headspace with my gauges. The bolt closes all the way down on my .74 gauge. Now some say shoot it anyway they are supposed to be generous. I measured the bolt head and it measures at .63. My question is can I install a longer bolt head to correct and lessen the head space. I know that the no.4 lees are done this way. Thank you.
 
If you can find a longer head, and if it fits properly, that would tighten headspace. It will be a matter of trial and error.
 
As above, the Mk 111 bolt heads are not marked according to size, so you are reduced to trial and error. If you plan to reload, then you can simply size the case to the chamber, and your headspace problem is solved. BTW - Case life and accuracy are benefitted as well..
 
cosmic said:
As above, the Mk 111 bolt heads are not marked according to size, so you are reduced to trial and error. If you plan to reload, then you can simply size the case to the chamber, and your headspace problem is solved. BTW - Case life and accuracy are benefitted as well..
Click to expand...

I recall reading an article that explained how to do this. I believe you expand the .303 neck up to 8mm. Then you size it down incrementally in a .303 size die which begins to set the shoulder, essentially creating a second shoulder on the cartridge ahead of the original. Once the round will chamber you stop sizing the shoulder further down. Load it, fire it and the case will fireform with the new case shoulder in the proper location for that chamber. After that only neck size the case. The new shoulder prevents overstretching of the case and eventual case head separation.
 
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That procedure works.
Or a small o-ring or pony tail band can be slipped over the case in front of the rim to hold the casehead back against the boltface. Once fireformed, treat the cases as if they were rimless, headspacing on the shoulder.
 
Hi there. First off the #1 mk. 3 bolt-head is not the same as a #4 which you probably know. I have the bolt head you need but it has to be measured to see if its right size. Marstar also sell the bolthead.
 
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My No.1 MK3 had a lot of headspace when I got it. It almost closed on the no-go guage. I had 3 spare bolt heads kicking around and one of them was longer than the others (can't remember exact measurements but I can get them if you want). I put the new one on and it fit like a glove. No over travel when winding on the newer bolthead either.
My head space was perfect according to my gauges and my groupings got better as well :)
To be honest I believe I got lucky with having the right one I needed and it fitting properly.
 
I got that after posting this. I had an aha moment while doing something else. What I need is a bolt .005 longer. I think I will just keep searching by trying any I can get my paws on.
 
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