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Notch on bolt head

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=8614
Printed Date: March 28 2024 at 10:46am
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Topic: Notch on bolt head
Posted By: DeeCeeTee
Subject: Notch on bolt head
Date Posted: November 06 2017 at 7:10am
Hi Guys. I am new to No 1 Mk3*s and in pursuit of minimilizing the head space I ordered several head bolts from Liberty Tree and some are notched and some are not. What is the deal with the notches? The ones with out the notches seem to be very tight and do not 'clock' correctly. What is the deal with bolts marked DP? I have one of those also. Can you help me? Thanks.



Replies:
Posted By: A square 10
Date Posted: November 06 2017 at 7:44pm
the DP marked is "drill purpose" only but i would not think it would affect the use of a bolt head if it headspaced correctly , 


Posted By: Shamu
Date Posted: November 07 2017 at 5:24am
I'd honestly not use the DP stamped ones. See if they'll swap them for non DP.
Can you show a pic of this "notch"


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


Posted By: Bear43
Date Posted: November 07 2017 at 6:01am
Are you referring to notched and non-notched like the ones in the following picture? If so, the notched one was an earlier design meant to facilitate removal of the striker. Since that was deemed unnecessary eventually the non-notched design came about. They don't necessarily interchange either. I have found that non-notched bolt heads tend not to work on earlier bolt bodies and I have seen notched bolt heads that wouldn't turn into a later bolt body. You just have to keep at it until you find one that works with your bolt body. Also, please do not use a DP marked bolt head. They were marked DP for a reason, don't risk your life with DP marked pressure bearing parts.




Posted By: Shamu
Date Posted: November 07 2017 at 9:05am
Well I'll be. . .
learn summat every day round here.Thumbs Up


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


Posted By: DeeCeeTee
Date Posted: November 07 2017 at 9:09am
Hi, Thanks for the reply. The original bolt/bolt head that came with the rifle has a notch in it and the replacement bolt/bolt head that I ordered from Liberty Tree does not and the bolt and the Cocking Piece have DP stamped on them, not the bolt head. Here are pictures of the two bolts. Any help on the letters/symbols on the bolt heads would be wonderful. Or is there a place to go on the web that explains the manufacturers stamps on the web?   


Posted By: DeeCeeTee
Date Posted: November 07 2017 at 9:14am

Here are some more pictures. I did not know how to attach multiple photos.


Posted By: DeeCeeTee
Date Posted: November 07 2017 at 9:24am
Bear43,
     The silver headbolt is .643" and the blue headbolt is .634". The blue bolt/headbolt combo close on NG and do not close on the FIELD. I have not tried on the okie headspace gauges yet. I thought if I put silver headbolt on my bolt I would close the headspace down by .009" and be back in the G-NG area. When I tried it the silver bolthead was really tight when screwed in and I would have had to use some muscle to get it to align (clock) at 1200 for installing it. So i stopped and wrote in. Thanks again for the info and thoughts.
   DeeCeeTee


Posted By: Canuck
Date Posted: November 07 2017 at 11:06am
I had no idea a notched bolt head for the #1 rifle even existed. Thanks for enlightening us, Bear!

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Castles made of sand slip into the sea.....eventually


Posted By: Zed
Date Posted: November 07 2017 at 12:08pm
I had noticed the notch on a couple of the bolt head's that I have for the No1 rifle. I did no the reason for it. So thank you Bear! it's nice to learn something new.

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


Posted By: Bear43
Date Posted: November 07 2017 at 1:03pm
Glad to be of some help! Stuff like this has to be shared about so we don't lose it. Thumbs Up


Posted By: Shamu
Date Posted: November 07 2017 at 1:54pm
I'd be really, really nervous about using those DP marked parts.
Seriously how do you know they aren't out of gauge, or haven't been softened for example?


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


Posted By: Bear43
Date Posted: November 07 2017 at 6:22pm
DeeCeeTee, I think you are overthinking the headspace. Do not go by Go/No Go, go only by the Field gauge and only use the proper military field gauge. If you were using SAAMI spec gauges, they are all wrong for these rifles. Also, the Go/No Go is only used for fitting barrels while the Field is used to check serviceability. So first, get the Okie gauges. Second, return those DP parts to Liberty Tree, do not use any pressure bearing DP parts including bolt body and head. Even the DP cocking piece raises overall safety concerns. We will help you get this sorted, just take your time in all of this.


Posted By: DeeCeeTee
Date Posted: November 07 2017 at 10:16pm
Hi Bear43,
     I will follow your advice and send the DP bolt assy back and ask for a non-DP one. I had ordered a set of the Okie gauges and they just showed up yesterday, I will try those on my original bolt and let you know. I also ordered 4 bolt heads to try and find a longer one, they are in the mail right now. Right now I am shooting military surplus brass, but plan to reload as I accumulate my brass.  Is headspace more critical on military ammo or reloads? Or am I being OCD about the issue.
   Thanks, Dave


Posted By: Shamu
Date Posted: November 08 2017 at 5:14am
H/S is about longer brass life.

I think you are being a little OCD with it. Its a simple pass/fail option. Bolt closes on an 0.074" FIELD = FAIL, everything else = GOOD.

To put it into perspective I'd rather have a non DP that just barely passes than a DP that passes with flying colors.


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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: November 08 2017 at 11:41am
Shamu; I think you've got it the wrong way around! 
If the bolt closes on the "Field" gauge it's a FAIL. Because head space is over 0,074". 
If it does not close on the  "Field" gauge the the head space is GOOD, because it's less than the 0,074" limit.
The 0,064 No Go is only really useful if changing a barrel or new bolt body.



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


Posted By: DeeCeeTee
Date Posted: November 08 2017 at 11:49am
I used the okie gages today. bolt closed on G and NG, but not on the F. This is with the bolt that came with rifle. Non DP. So I think I will try measuring the 4 head bolts to see if any are longer than my head bolt and try them accordingly. Thanks for all the info guys, and especially you Bear43.Smile 


Posted By: Shamu
Date Posted: November 08 2017 at 1:30pm
Originally posted by Zed Zed wrote:

Shamu; I think you've got it the wrong way around! 
If the bolt closes on the "Field" gauge it's a FAIL. Because head space is over 0,074". 
If it does not close on the  "Field" gauge the the head space is GOOD, because it's less than the 0,074" limit.
The 0,064 No Go is only really useful if changing a barrel or new bolt body.


Yes you're right I brain pharted. Thanks.


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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: November 08 2017 at 1:35pm
Don't get fascinated by length, there are other things to consider also. If the 0.074" did not close it passed, there's no need to "extra pass". Its pass/fail, you don't need to "meet or exceed", just not fail.

The bolt head should over clock (past aligning with the bolt's rib by no more than 15 degrees. ( a bit less is fine but there should be  some.)
The reason for this is that the shoulder of the bolt head should transfer the pressure & recoil impulse directly to the front face of the bolt body. If its more than the 15 degrees (also 1/16" from the 2 corners of the bolt head & the bolt ribs corner) then the threads are doing this instead.


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


Posted By: englishman_ca
Date Posted: November 10 2017 at 6:42am
Morning ramblings while I drink my first coffee.....The bolt head with the notch was introduced with the Sht.LE Mk.I around 1903.

The bolt could be dismantled without tools for cleaning.  The striker retainer screw at the back of the cocking piece was more like a spring loaded knurled knob to be gripped, pulled and given half a turn to release its hold on the striker.
The striker had a corresponding lug on the collar which fitted into the notch. In effect, the bolt head then became a wrench to unscrew the striker.

As with all crunchies, anything on a weapon that could be unscrewed and fiddled with would be unscrewed and fiddled with. It was then thought that maybe the army didn't want a soldier dismantling his bolt in the field, so the feature was discontinued around 1907.

Since there were many, many rifle still in circulation with the striker with the lug and notch combo, current production of the bolt head with the notch had to continue to allow for any replacement bolt head to have a universal fit.
So a notched bolt head could be described as a Sht.LE Mk.I bolt head, although they were actually manufactured for many more years even though obscolete.

DP means drill purpose. Drill as in training, not just parade marching on the drill square. A soldier had to be taught how to load, unload and do all the other good stuff, sometimes ham fisted. Not a good thing for a live rifle that would be expected to be taken to the range or into battle and shot.

The British had a maintenance schedule for each and every firearm in the British inventory. Once a year, traveling armourers would inspect each rifle with gauges to ensure that it was in tip top condition. Can you imagine the logistics of doing this? But that is how it was done. A huge expense of time, money and resources.
DP rifles were not in this maintenance routine. They got zero inspection. No need, they would never be used for live fire. 

So if you find a DP rifle, that tells you that it has had zero maintenance while in service while marked as such.

Now some people will argue that although armourers would take poor condition rifles and parts that were deemed unserviceable, usually due to wear or some other serious problem and convert them, if there were no scrap rifles available for conversion to DP, perfectly good rifles would be pulled from stores and converted. Yes. that did happen but there are no differentiating markings to distinguish so.

It could be that the rifle is just fine. It could be one of those perfectly fine rifles that were pulled from stores. It could be worn and not economically repairable. It could have a cracked receiver. It might look perfectly fine but had been in a flood or a fire. Ya just never know as to why a rifle was made DP. So it is Russian roulette if you were to shoot one.

I have noticed that most of the people that argue that some DPs can be shot are the owners of such.
I confess that I have shot some of my DP rifles but I have gauges and can do an inspection a bit deeper than most people, but it is still a judgement call on my part. 18500 lbs per square inch of an instantaneous pressure spike going off inches in front of my face. 

DP marked arms are not intended for shooting, period. You are an adult, do your own risk assessment.



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Look to your front, mark your target when it comes!


Posted By: Shamu
Date Posted: November 10 2017 at 1:31pm
So it was both a different striker (with a "pin", instead of 2 cuts), a different locking mechanism for the striker in the cocking piece AND a different bolt head. All of them carried over from a different rifle?
Wacko
That would explain why I couldn't figure it out!
Confused


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


Posted By: Bear43
Date Posted: November 10 2017 at 5:50pm
I took pictures tonight of an early bolt I have to illustrate it all, Shamu. I will get them posted up over the weekend.


Posted By: Shamu
Date Posted: November 11 2017 at 9:15am
Thanks.

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


Posted By: Bear43
Date Posted: November 22 2017 at 12:44pm
I spaced this out completely. First picture is the older and newer strikers. Older bottom, newer on top. The only difference is the nub standing proud on the older style. The second pic shows how it fits in the bolt head. To remove these strikers you remove the locking screw, turn the cocking piece to the "fired" position then simply turn the bolt head out while unscrewing the striker. The thing to note is that these strikers and bolt heads must fit together like this in the "fired" position so the collar on the striker mates with the base of the bolt head.






Posted By: Shamu
Date Posted: November 22 2017 at 1:55pm
Excellent! Thanks.
Hug


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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: November 23 2017 at 11:34am
"A picture paints a thousand words"
Thanks Bear. That is worth knowing!


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


Posted By: paddyofurniture
Date Posted: November 23 2017 at 3:33pm
Thank you for showing me something new about Enfield's.

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Always looking for military manuals, Dodge M37 items,books on Berlin Germany, old atlases ( before 1946) , military maps of Scotland. English and Canadian gun parts.



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