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Bolt and headspace

Printed From: Enfield-Rifles.com
Category: Enfields
Forum Name: Enfield Gunsmithing
Forum Description: Submit any how-to's or other gunsmithing suggestions here.
URL: http://www.enfield-rifles.com/forum_posts.asp?TID=7962
Printed Date: March 28 2024 at 6:00am
Software Version: Web Wiz Forums 12.04 - http://www.webwizforums.com


Topic: Bolt and headspace
Posted By: halsem
Subject: Bolt and headspace
Date Posted: March 26 2016 at 9:50am
I'm sure that this is not a new topic but I am new to owning Enfields and would appreciate input.
My No. 1 Mk3* appears to have headspace issues (it practically closes on 0.074" gauge).
The bolt head is 0.630"
I have used Sharpie to see lug engagement and the long lug appears to be engaged about half its length.  The short lug barely engages.  You might just see that the tip of the lug has ink missing.
Is this destined to be a wall hanger?  I sincerely hope note.  If you guys think there is hope, I will send it to a gunsmith for a safety and headspace check.
I have read on here about stoning the lugs to get better engagement but would that increase the headspace even more?



Replies:
Posted By: Zed
Date Posted: March 28 2016 at 1:57pm
Stoning the lugs will increase the head space a little, so I'd get a longer bolt head sorted first.

If my memory serves correctly; I believe your bolt head is short. I believe a new SMLE bolt is around 0,636". They were often shortened to give correct fit to the bolt. You should be able to get one longer than what you have. But you may have problems with a different bolt head clocking in to the correct position; 
I had to buy a couple; what I have noticed is that there are 2 types of bolt head. One version has a notch out of the begining of the screw thread, the other does not have the notch cut out. 
On my no1 MkIII* I've found that the bolt heads without the notch clock in properly, and the ones I have with the notch do not. However I only have one no1 rifle and a few bolt heads; so there may be more options that I'm not aware of.


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It's nice to be important, but it's more important to be nice!


Posted By: halsem
Date Posted: March 29 2016 at 3:39am
This sounds simple, so I'm sure there is a good reason against it.  Why can't you put a shim washer over the bolt head threads which would effectively push the head forward by the thickness of the shim?



Posted By: Shamu
Date Posted: March 29 2016 at 5:18am
"Just barely" isn't necessarily a bad thing.
Headspace is a pass/fail proposition if the gauge doesn't FULLY close with light pressure from a single finger then its a PASS.
Stoning is something to do only if you're 100% confident of your knowledge & skill levels so approach it cautiously.

You can't shim for several reasons. shock to the shim & threads, bolt over-turn & firing pin protrusion being 3 of them. Additionally the stop collar is required to strike the shoulder inside & shimming would not permit that.


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Don't shoot till you see the whites of their thighs. (Unofficial motto of the Royal Air Force)


Posted By: Shamu
Date Posted: March 30 2016 at 7:35am
Do you have an FP Protrusion gauge?


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Don't shoot till you see the whites of their thighs. (Unofficial motto of the Royal Air Force)


Posted By: halsem
Date Posted: April 03 2016 at 3:45am
I had the rifle checked by a gunsmith and it does fail Field headspace.
My bolt does not have the notch so I will try with another bolt head. Problem is most sites don't indicate the size of the head and as most are probably used it might be a bit hit and miss.
I also watched the Midway USA video about ncreasing bolt locking lug contact through the use of lapping compound instead of a stone. Wouldn't this also affect the receiver as they are cycling the bolt through the receiver ?

Any thoughts?

Matt


Posted By: Zed
Date Posted: April 03 2016 at 1:19pm
Lapping the the bolt with grinding paste is NOT a good idea! The receiver contact area is case hardened; but apparently not very thick so could wear through.

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It's nice to be important, but it's more important to be nice!


Posted By: halsem
Date Posted: April 03 2016 at 6:51pm
Can you confirm the size(s) of your No 1 Mk3 bolt heads?


Posted By: halsem
Date Posted: April 05 2016 at 11:47am
Most bolt heads I see are around 0.630" so I am now wondering if the lugs on the bolt body are worn down rather than the head itself.  Any suggestions on how I can check which part is actually worn?



Posted By: halsem
Date Posted: April 11 2016 at 1:18pm
So I bought a New Old Stock bolt because I feel that the shoulders are worn on my current bolt.
When I tried to screw the old bolt head into the bolt body it doesn't screw in all the way.  Anyone experience this before?  I know I can cut the threads back on the bolt head but I really don't want to do that.  The head protrudes by about 1/8 in ahead of the bolt body.


Posted By: Zed
Date Posted: April 13 2016 at 11:59am
Don't go cutting anything. The firing pin will need the shoulder of the bolt head to stop against.
You need to check that the thread in the bolt is clean all the way down. If the bolt head is not winding up to the shoulder then it is probably just crud in the threads. However, when that's clean the bolt head needs to screw in to the shoulder and align properly (clock in) with the long lug rib.
You may need to try different heads to get a good clocked in position.


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It's nice to be important, but it's more important to be nice!


Posted By: Shamu
Date Posted: April 13 2016 at 2:48pm
Originally posted by Zed Zed wrote:

Don't go cutting anything. The firing pin will need the shoulder of the bolt head to stop against.
You need to check that the thread in the bolt is clean all the way down. If the bolt head is not winding up to the shoulder then it is probably just crud in the threads. However, when that's clean the bolt head needs to screw in to the shoulder and align properly (clock in) with the long lug rib.
You may need to try different heads to get a good clocked in position.

^^^^
THIS!
There's more to the bolt fitting than just screwing it in fully. Please research more before you cost yourself a fortune in parts.



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Don't shoot till you see the whites of their thighs. (Unofficial motto of the Royal Air Force)


Posted By: Zed
Date Posted: April 17 2016 at 1:04pm
I had the opportunity to check the size of my No1mkIII bolt heads. 
They are from 0.634" to 0.637" the longer being an unused one. So I would strongly suggest looking for a longer bolt head than the 0.630 that you have. 
Remember that the difference between the Field and the No-Go gauge is only 0.004" 
Therefore a long bolt head means you do not need to replace the original bolt. Which could save a lot of work and potential heartache.


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It's nice to be important, but it's more important to be nice!



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