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Bolt Head issues

Printed From: Enfield-Rifles.com
Category: Enfields
Forum Name: Enfield Rifles
Forum Description: Anything that has to do with the great Enfield rifles!
URL: http://www.enfield-rifles.com/forum_posts.asp?TID=11667
Printed Date: March 28 2024 at 2:19am
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Topic: Bolt Head issues
Posted By: g_legris
Subject: Bolt Head issues
Date Posted: September 29 2021 at 10:00am
On a sporterized No 2 Mk I* I initially had issues with the bolt cocking piece.  Many thanks to the members who helped me fix this.

This gave me a chance to really test fire the rifle.  The good news is that it produces tight groups.  It now has an issue with the bolt head.

When I chamber a round the bolt is extremely difficult to close.  Upon further inspection it appears that the bolt head is too long.  The head measures 0.631" long and has no gap between the face of the bolt head to the chamber.  There is insufficient room for the cartridge rim.  When I checked my other SMLEs I can clearly see a narrow gap between the bolt head and the chamber.

I have found bolt heads for sale, but they are marked size 0 and size 1.  I have no idea what my current bolt head is, but another post on this forum indicates it is a size 2 or possibly a size 1.  If this is the case, it seems a size 0 would give me an additional 0.005" to 0.010".  I am unsure if this is enough.

I found a a 0.064" armorer's headspace gauge for sale.  Would this be useful?

Attached are images of the bolt in locked position and the markings on the bolt head.

Thank you.








Replies:
Posted By: Zed
Date Posted: September 29 2021 at 11:17am
This seems a little bit odd! 
The bolt head you have should not be too long; it looks like a 0 stamped lightly in the photo.
So I have a few questions! (also you rifle is a No4Mk1*)

1: Is the bolt matching number to the rifle?
2: Is this the original bolt head
3: Are you reloading the ammunition or is it new factory ammo?
4: Is it difficult to close on an empty chamber?
5: What has been worked on or changed; since it was working properly?

A 0.064" Go gauge is a good idea


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


Posted By: g_legris
Date Posted: September 29 2021 at 12:14pm
Sorry, don't know why I typed No2, it is indeed a No4MkI*

To answer your questions, in order:

1. The bolt has the same number on it stamped as on the receiver band behind the trigger.  The magazine has the same number.
2. I do not know if this is the original bolt head.  The rifle was purchased used, hence I have no idea what a previous owner may have done.  It was purchased from a dealer, not an individual.
3. I am using factory ammunition.  I most recently used Remington 174 grain.
4. Yes! it is difficult to close on an empty cartridge.  I have tried Remington, Fiocchi, Winchester, Sellier & Bellot, etc.
5.  It has always had this issue since I purchased it.  The only thing done was to replace the cocking piece.  The cocking piece it came with had exactly the same cartridge loading issue and it would not half-cock; it went straight to full cock.  If anything, it was worse with the old cocking piece.

I do see the zero (0) stamped on the bolt head.  Nonetheless, the bolt head measures 0.631" which is longer than the specification for a size 0.  I understand that a size 0 should measure 0.620" to 0.625".  I found this information from a post by Alan de Enfield on this forum posted on February 07, 2012.  The post indicates that the specifications may not be followed very well as he found a number of size 0 bolt heads longer than 0.625".

One of the sites that has bolt heads for sale is within a 45 minute drive from me and I can go and measure the bolt heads to see if they are shorter.  The other alternative is to take the bolt head to a machine shop and take off 0.005", if this is the what needs to be done.

I am beginning to think whoever owned the rifle previously may have reassembled the bolt with random parts.  The remainder of the rifle seems fine.

As for the 0.064" gauge, is it a Go or no-Go gauge?  I have seen conflicting comments on this.


Posted By: britrifles
Date Posted: September 29 2021 at 12:19pm
something not making sense.  You test fired the rifle and it was fine?  Did you feel any resistance in locking the bolt with a round in the chamber?  If you do, do not fire this rifle until this is resolved. 

Are you sure the bolt head was fully screwed onto the bolt when you discovered the problem (presumably after you fired the rifle)?  It looks like the bolt head is screwed all the way onto the bolt in the photo. 


Posted By: Shamu
Date Posted: September 29 2021 at 12:57pm
0.064" is a GO gauge
(Headspace gauges generally come in 3 sizes:

GO: measures the minimum acceptable headspace. This size is most often used when re-barreling or re-chambering a firearm.

NO-GO: This gauge is used to check for excessive headspace. If a firearm closes on the NO-GO gauge it is an indication that the weapon MAY not be safe to fire. Reloading ammunition for a firearm that fails NO-GO can result in unsafe loads due in part to the expended brass being elongated as a result of not being firmly chambered. Most military surplus firearms that pass NO-GO (the bolt will not fully close on the gauge) are considered safe to fire with surplus ammunition, or with modem loads not intended for reloading.

FIELD: A firearm failing the NO-GO spec can be tested on the slightly more forgiving FIELD gauge. Military chamber specifications are generally looser than commercial firearms, giving them a bit of tolerance for adverse conditions such as dirty chambers, weather extremes, etc. A firearm passing FIELD spec (not closing fully on the gauge) is generally considered safe to fire the ammunition it was designed to fire, i.e. military surplus ammunition of the designated caliber.)

what you need is a NO-GO,(0.067")

or to be precise a FIELD, (0.074")

NO GO is a U.S. spec, the British just used a "Too short" & a "Too Long"


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


Posted By: g_legris
Date Posted: September 29 2021 at 1:20pm
Thanks for the info on the gauges.  I'll see if I can find one somewhere.

As for the rifle: When I first tried to fire the rifle the bolt was hard to close.  It seemed something was wrong so I did not mess with it much.  Initially, I thought it was the old cocking piece.  Even without a cartridge it was hard to close.  Upon examination, the cocking piece seemed rather damaged.  The cocking piece was replaced with another No4 MkI* cocking piece and it worked much, much better.

I went to the range and loaded the rifle.  It was quite hard to close the bolt.  I am not shooting the rifle until it works as expected.


Posted By: Zed
Date Posted: September 29 2021 at 1:40pm
Ok, if you have always had this issue; it's probably an incorrect replacement bolt head.  It would be worth checking with the proper gauge. A shorter bolt head should be easy to find. 

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


Posted By: g_legris
Date Posted: September 29 2021 at 2:01pm
Thank you for the input.

I have ordered Forster GO and FIELD gauges.  They should ship in a few days.  A NO-GO gauge, original British Armorer's, is available not to far away and I can go check it out, as well as bolt heads.  Actually, I think a NO-GO is not needed, the bolt is too tight not giving any headspace at all.

BTW, the bolt head is screwed in all the way. Wink

Many thanks to all for the great feedback.


Posted By: Goosic
Date Posted: September 29 2021 at 2:35pm
g_legris. Your comment, "0.631" which is longer than the specification for a #0 bolthead" is skewed.  The boltheads have been found in many instances to NOT fall into specific categories with regard to individual sizes.  You can find a #1 longer than a #3, a #2 smaller than a #0 and so forth. In your case you should be looking for a #0 with a 0.628" - 0.626" length.  The optimal solution would be for you to carefully stone the face of the bolthead until you get the desired clearance. When get home tonight,  I'll check my spares. I think I have a .0628" #0 bolthead. 


Posted By: Shamu
Date Posted: September 29 2021 at 2:57pm
A thought on Gauges.
You need
0.064"
0.067"
&
0.074"
THIS is what's important, because of the "dual" SAAMI & Brit specs.
Its not the NAME that's important but the actual measurement.
I believe the Forsters are SAAMI spec, which is going to give you some issues.
Please check before you get burnt.


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


Posted By: Goosic
Date Posted: September 29 2021 at 4:01pm
I looked through my spares and all I have left is a #3 that measures @ 0.6385" Sorry I couldn't be of assistance...


Posted By: britrifles
Date Posted: September 29 2021 at 7:00pm
I have several #0 and #1 bolt heads.  I’ll check the measurements when I get home this weekend.  But, as Zed has said, these sizes are not hard to find.  

Before you go buy a new bolt head, check headspace with the gages first.  Although very unlikely the cause of the problem in the .303, clean the chamber with a bronze brush to be sure no carbon build up in the neck/shoulder area. Make sure no crud is built up at the rear edge of the chamber.   Most likely the cause is a mismatched bolt head. 






Posted By: g_legris
Date Posted: September 29 2021 at 7:14pm
Thank you Goosic for looking for an appropriate bolt head.  I'll purchase a spare bolt head and stone it down if I need to do so.  I have the equipment to do that and keep the face perpendicular to the axis.

Also, thanks to Shamu for the warning about the Forster gauges.  They are SAAMI specified, not British.  I did find a set of gauges from an Austrian company called Tectal.  Their gauges are 0.064, 0.068, and 0.074".  They are essentially disks as opposed to gauges that fit partway into the chamber.  The set costs about $62 plus shipping.  Not sure how long it would take to get them.

Britrifles, many thanks for checking on this.  There is someone nearby who has some and I'll go see what he has.  He also has an original GO (0.064") gauge.


Posted By: britrifles
Date Posted: September 30 2021 at 8:43am
g_legris, if you want to wait a few days, I’ll check the measurements on the spare bolt heads I have, I’d be willing to trade one for the bolt head you have.  


Posted By: Shamu
Date Posted: September 30 2021 at 9:51am
OK, yes, "Coin" type gauges.
That's what I have myself, they're just as accurate & easier as well because you don't need to strip the bolt to use them.


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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: September 30 2021 at 12:30pm
Regarding the SAAMI spec gauges; I would say they are OK if you are wanting minimal clearance between bolt face and case. Which would be useful when reloading, due to the reduction in case stretch.

However the problem with the SAAMI spec is that if it fails there "NO GO" gauge, you may be condemning a perfectly good rifle; because it would probably pass the proper British Army spec'; because it is 0.004" thicker. 

Also; a note on using the gauges! Do NOT force the bolt when it contacts the gauge!
What you want is thumb and fore finger, just lower the bolt handle gently until you feel it stop on the gauge.



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


Posted By: Shamu
Date Posted: September 30 2021 at 2:10pm
Actually I don't even use the thumb!
I pull the trigger & leave it pulled to reduce spring tension & just go down with the pointing finger.
There's a LOT of mechanical advantage involved in camming the bolt closed.


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


Posted By: britrifles
Date Posted: September 30 2021 at 3:12pm
The beauty of the Lee Enfield design is that you don’t have to condemn a rifle with excessive headspace, you just replace the bolt head with a longer one!  That of course has its limits too.


Posted By: g_legris
Date Posted: October 01 2021 at 8:44am
Thank you for the replies.

I appreciate the offer of a bolt head swap from Britrifles.  Let's wait and see what I need.  I have placed an order for a set of gauges and am planning to pick up an original Enfield armorers 0.064" gauge on Monday.  That will give me an idea how far off my current bolt head is.  It will also give me a chance to see how my No 1 MK III*s are set up.  They work fine, but one of them may be close to the FIELD limit.  It would be nice to set them up properly and see if any of them should be marked DP.  I hope not.

Thanks again for all the help


Posted By: britrifles
Date Posted: October 01 2021 at 5:48pm
g_legris, the shortest spare bolt head I have measures 0.629, only 0.002 shorter than your bolt head.   Let me know if the bolt wont close on the GO gage, you might want to see if the 0.629 bolt head will work before stoning down the one you have.



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