Lee Enfield Bolt-Head Metal Composition?

[HollowPoint]

Do any of you more knowledgeable Enfield guys know what type of metal was used to make the Bolt-Heads on the Enfield No.4's?

It seems that in my search for one of the right length, the longest one I could find measured short; and it has the #3 stamped on it. (.635)

These guns were made in so many different places that it stands to reason that the specs on them would differ greatly.

If I can find out what type of metal (or an equivalent metal) they were made of I'm about 75-percent sure I can make a safe working copy of a Lee Enfield bolt head.

I know there are alot of guys here that have alot of smarts when it comes to the Lee Enfield. If possible, I'm just looking for straight answers and maybe some insight on the manufacturing technique used to make these little gizmos. No lectures please.

I had to come back and edit this post cause I almost forgot to ask something else pertaining to these Lee Enfield Bolt-Heads. Anyone know what the thread pattern is on the tail end of these Bolt-Heads?

Thanks in advance.

HollowPoint

[Multigunner]

The SMLE specs called for No.34F Special Gun Iron, a very pure malleable "white" cast iron with an extremely high resistance to compression. This metal also has an unusual ability to old lubricants like a bearing, which reduced thread wear.
These were casehardened.

I don't know if other metals or alloys were used for the No.4 but I suspect simple cast steel may have been used as well. Drop forged might be better though.

Edited to add
The Specs for the SMLE boltheads made from 1938 onwards were
"Head, breech bolt -- Steel B.S.S.5005/103 -- Case hardened and polished"

So its likely this steel was used for the contemporay No.4 boltheads.



The M marked boltheads are Cast Iron, the M stands for "Mild Steel" but White Cast Iron is listed as mild steel in British metallurgy hand books.

While resistant to compression the cast heads have less shear strength than steels.

Threads for the SMLE Boltheads are diameter .4175 X 20 TPI
The No.4 dia .4375 X 20 TPI



If I can find out what type of metal (or an equivalent metal) they were made of I'm about 75-percent sure I can make a safe working copy of a Lee Enfield bolt head
If successful you could sell a boat load of #3 boltheads, those are scarce as hens teeth.
A #4 bolthead was made but not used as the British figured a rifle that needed one was worn past safe repair, but such a long head would be very helpful for those who reload and want absolute minimum headgap with undersized commercial cases.

You might consider countersunk boltheads with plunger ejectors suited to the .223 conversions. A British firm made these and was charging $90 apiece for them, I doubt they had many takers at that price.

You could look for a download of the SAID (Small Arms Identification drawings) for the No.4 , these may have a detailed mechanical drawing of the bolt heads with dimensions. The NRA site has these but not downloadable due to copyright issues.
I had found a full set for the SMLE, No.4, and P-14 but a crash wiped my files. I haven't found another source yet.

[nicholst55]

Last I heard, Brian Dick at BDL, Ltd. (http://www.bdlltd.com/) has NOS (new, old stock) #3 Lee Enfield bolt heads in stock. He doesn't list them on his website, so I don't know how many he has or had, or even if he still has any. They weren't cheap, but they are new and unfitted.

[HollowPoint]

Multigunner:

That's exactly the type of information I was hoping for. Thanks very much. I really appreciate it.

In the back of my mind I was thinking I might be able to use (as my stock metal) a large diameter Grade-8 bolt to carve my replacement Bolt-Head out of, then I could heat treat that finished Bolt-Head.

Since the term, "Mild Steel" is used to describe the metal used to make these Bolt-Heads, it sounds like a Heat-Treated Grade-8 bolt metal may be of sufficient strength to use as a replacement metal.

Does this line of reasoning make any sense?

nicholst55:

I checked out the link you provided but, I didn't come up with anything on the Bolt-Heads in question.

Anyhow, I was hoping not to have to shell out any more money on Bolt-Heads.

Barring any unforeseen financial set backs, I'll be ordering a 4-axis CNC mill in October. I'm pretty sure I can use it to make up a replacement Bolt-Head of the right dimensions. I just want to make sure I'm using the right kind of metal.

No sense in taking any chances. I've already had one Lee Enfield blow up in my face; literally.

HollowPoint

[3006guns]

I think I'd hesitate using a grade 8 bolt. Nothing wrong with the idea, but the heat treatment can lead to fatigue. I know, I've had it happen when just such a bolt was put under repeated cycling while under a load. The grain structure at the site of the break had a crystaline appearance......brittle.

A grade 5 would probably be better as it's somewhat more elastic, yet still tough.

Why not simply order annealed drill rod of the correct diameter, machine and heat treat? The metallurgy is more tightly controlled so you KNOW what you're getting. Also a lot cheaper than buying a bunch of bolts!:bigsmyl2:

[HollowPoint]

Believe it or not, Drill-Rod was also on my list of potential candidates for metals I might be able to use for making me a replacement Bolt-Head.

Because I'm not really to knowledgeable when it comes to metal composition, I thought it prudent to ask around. It seems to be working cause even though I've only gotten three responses to my inquiry, all three have given me some real good information.

I know what you mean about the price of Grade-8 bolts. I use them to make my own reamers on rare occasions and the price of each bolt can be outrageous.

HollowPoint

[MtGun44]

Mechanical engineer here - Grade 8 bolt is a top quality steel, heat treated for strength,
and MUST be stronger than 150,000 psi. This is much more than any cast iron that
I am aware of, away from home at the present time, can't check my references to
be 100% certain. Certainly a grade 8 bolt is not brittle, but it will not be as malleable as a
Grade 5 bolt. This should not be a problem in this application, but a Grade 5 is
still rated for 120,000 psi ultimate tensile strength.

In any case, I'd be perfectly comfortable with making a SMLE bolt head from a Grade 8 bolt,
or from even a Grade 5 bolt, since the bolt is in compression, and the lugs are back on the
body, this should give you quite a large margin of strength. In my experience, the
aircraft bolts (AN series) machine a bit nicer finish right off the bat. I have made a number
of gun parts from AN series aircraft bolts, which have an ultimate tensile strength specification
of 120,000 psi, too.

Make sure you get your bolt from a reliable supplier, MANY bolts today are counterfeit, and in
the aerospace industry, we are all demanding a reliable paper trail from the supplier back
to the certified manufacturer. Some Chinese and Japanese bolt maker have been making
low grade bolts with fake SAE or AN head markings.

Bill

[Multigunner]

You might as well use the strongest available steel you can find, since its a reproduction of a bolt head theres no need to limit yourself to the materials they used long ago to allow economical mass production with the equipments at hand.

Using a stronger bolt head should increase the safety factor somewhat, though strength of the other load bearing parts remains the same.
Almost all Enfield action failures involve a broken bolthead, its the first thing to go and when it does pressure on other parts is instantly relieved.
Only other bolt part I've seen broken in photos was the lefthand bolt lug. The bolt body at that point is a simple tubular piece of steel, other than the guide rib on the opposite side, and the lug itself is not that substantial. That lug broke away taking a chunk of the bolt body, leaving a hole in the body, rather than shearing at an angle as a Mauser or Springfield lug would.

Making replacement bolt heads could allow one to custom fit the threads to take up slack in the threads of a worn bolt body. Armorers had access to bolt heads with minor variations in thread diameter, so they could use these to improve the fit by trial and error. They also recycled bolt heads, since a bolt head that over clocked due to wear might fit another bolt body perfectly, and a tried and true bolt head was usually more reliable than a new replacement.

A new replacement bolt head would improve the rifle, but without the accepted proof markings and manufacturers marks it would not improve collector value.
It could allow continued use of an original matching numbered bolt, which would prevent further loss of collector interest.
I had to replace the matching number bolt of my SMLE MKIII with a unissued BSA replacement bolt body and bolt head, due to excessive side play and overclocking due to wear. Headspace was fine with the old bolt, but it was still obviously on its last legs. Since the numbered bolt itself showed signs of being a very old armory replacement, and probably scrubbed and renumbered, it was no big loss and the new bolt will make the rifle a better and safer shooter ,if slightly less valuable.

If a bolt head with over sized shank were available I'd return the numbered bolt to its proper place.
Bolts are fitted to action bodies with no changes made to the action body, so returning the old bolt should cause no problems.

[HollowPoint]

I guess I'll be using either a Grade-8 or Grade-5 bolt then.

I figure when it came time to actually run the part, I'd make it out of soft aluminum stock just to see if I could actually do it. I don't see why I couldn't make one myself. The only way to find out is to try.

I may ruin the first two or three attempts but, ruining short pieces of aluminum rod is alot cheaper than ruining a couple of Grade-8/5 bolts.

I'm not to terribly concerned about collector value. This is an old Enfield that's just been collecting dust for about a year in my storage room.

This same Enfield is the one I've mentioned in a couple of different posts having to do with "Blowing up in my face." I never was able to figure out the How-or-Why of it. I'm just glad I wasn't hurt. (blew the bolt-head to smithereens though)

Since that time I've replaced the previous action with a different Barreled-Action. The latest Bolt-Head it wears is a #3 that measures .635". It's still to short for my liking but, it works just fine with mild loads.

I'll only be shooting low power cast bullet loads out of it but, in the event that it falls in to someone else's hands I want to be sure it doesn't blow up in their face should they decide to shoot full power loads.

HollowPoint

[gew98]

At least you got away safe. A buddy of mine in Oz had his near new 1942 dated remington 03 crack the receiver with a barely audible ping when shooting it. Being he's done alot of commercial flying the sound bothered him...he looked it over and sure enough the receiver cracked. Had he not heard that telltale sound the next round would have put him in the morgue.

[Vulch]

gew98 is right... that buddy is me!

First, let me relate a couple more recent episodes of the Springfield M1903 as related to me by a friend who is a competition shooter of milsurps in the USA (he uses K98's). In a recent match, not one, but 2 03's succumbed during the match - one sheared the kingscrew, the other, in typical 03 fashion, cracked the stock behind the tang of the action. Perhaps both shooters did not maintain screw tightness, but then that again is a failing of the 03 "design" (one Mauser overcame by timing the screws and using locking screws)

Anyway, to my 2 ruined 03's. Bill is wrong in one regard - it was not a Rem 03, it was a late 20's SA 03 and a LATE RI 03, assembled by SA in 1924 or there abouts. Please bear in mind these are not fantasy - they have been verified by Jim Beard and another well known 03 historian in the USA who always prefers his anonymity, but prints books.

Anyway, case by case:

1. Rock Island M1903, HIGH serial circa 1918 receiver, assembled in the mid-1920's by SA using an Avis 2-19 dated barrel. This is a HIGH NUMBER receiver. I was using factory 30-06 (Rem by memory - this is about 10 years ago now), when I heard a distinctly odd "twang" sound in the receiver. Odd, so I retired that rifle from firing that day cause I just did not like that sound!

Got the rifle home, disassembled it. There was a crack in the receiver running from the left index mark back to the Hatcher Hole. From the Hatcher Hole, the crack ran down to the front recoil/screw boss and across the bottom of the receiver. Scrap one 03!

I had that action cut with a wheel, and kept the front section (sold the barrel etc). I only recently threw it out when we moved house.

My odds couldn't get worse, could they?

2. SA VERY late 03 (inter-war). This one had a SHOT OUT barrel, so I decided to import a same-date barrel and rebarrel it. Barrel came out easy, and when the new barrel went in, it was perfect - only needed about a 20 degree wrench turn to align. We went to get the bolt so we could check headspace etc (I was with a certified gunsmith with 30 years experience who used to assemble rifles for Omark / MAB here in Australia). When we came back, the action had split for a good inch. We had assured clean threads on barrel and action, and all was within spec, but somehow, it just twanged open enough for us to be able to see barrel threads! Perhaps - as was surmised by Jim and some others, when the receiver was relieved of the pressure of the old barrel, it had "relaxed" somewhat, and when the new barrel was installed, it "stretched" it again, and pop.

Which makes one think just how brittle 03 receivers are! Metal fatigue even in the high numbers is obviously evident.

I swore off 03's from that day on. Not only did I no longer trust them, but they are HORRIBLE rifles to shoot, both in terms of comfort (that buttplate digs in like a darned razor after as few as 20 shots) and sights (and I had 25 year old eyes when I was shooting them). Those rear sights may be fantastic for a range shooter, but on a battle rifle????!!!! VERY serious flawed military suitability, as was borne out in WW1.

I'll never own another M1903. EVER.

Besides, MANY MANY military rifles will outshoot it - K98, Arisaka, and even a good Lee Enfield (I had in excess of 190 Lee Enfields in my collection at one point)

[Vulch]

You might as well use the strongest available steel you can find, since its a reproduction of a bolt head theres no need to limit yourself to the materials they used long ago to allow economical mass production with the equipments at hand.

Using a stronger bolt head should increase the safety factor somewhat, though strength of the other load bearing parts remains the same.
Almost all Enfield action failures involve a broken bolthead, its the first thing to go and when it does pressure on other parts is instantly relieved.
Only other bolt part I've seen broken in photos was the lefthand bolt lug. The bolt body at that point is a simple tubular piece of steel, other than the guide rib on the opposite side, and the lug itself is not that substantial. That lug broke away taking a chunk of the bolt body, leaving a hole in the body, rather than shearing at an angle as a Mauser or Springfield lug would.

Making replacement bolt heads could allow one to custom fit the threads to take up slack in the threads of a worn bolt body. Armorers had access to bolt heads with minor variations in thread diameter, so they could use these to improve the fit by trial and error. They also recycled bolt heads, since a bolt head that over clocked due to wear might fit another bolt body perfectly, and a tried and true bolt head was usually more reliable than a new replacement.

A new replacement bolt head would improve the rifle, but without the accepted proof markings and manufacturers marks it would not improve collector value.
It could allow continued use of an original matching numbered bolt, which would prevent further loss of collector interest.
I had to replace the matching number bolt of my SMLE MKIII with a unissued BSA replacement bolt body and bolt head, due to excessive side play and overclocking due to wear. Headspace was fine with the old bolt, but it was still obviously on its last legs. Since the numbered bolt itself showed signs of being a very old armory replacement, and probably scrubbed and renumbered, it was no big loss and the new bolt will make the rifle a better and safer shooter ,if slightly less valuable.

If a bolt head with over sized shank were available I'd return the numbered bolt to its proper place.
Bolts are fitted to action bodies with no changes made to the action body, so returning the old bolt should cause no problems.

Errrr.....

Overclocking bolt head is NOT a problem - it is DESIGNED to - it's SUPPOSED to rotate at least 10 to 20 degrees past alignment with the bolt rib. IF it lines up tightly WITH the rib, then it is OUT of spec and NOT corect and potentially a problem.

The entire design of the bolt is predicated upon the over-rotation of the bolt head so that the bolt does NOT lock up due to dirt ingress, misuse etc. It allows for problems to be ovecome.

You replaced something most likely NOT incorrect!!!

Most people who do NOT know the SMLE have no idea about what is right and wrong. The funniest I usually see in US publications is the magazine standing vertical in the triggerguard (so that the back of the mag does not lie flush against the bow) - I can GUARANTEE you'll get misfeeds doing that! It's not supposed to be vertical - it is supposed to be flush against the bow of the triggerguard, till the magazine snaps into place with a distinct audble click.

[Multigunner]

Errrr.....

Overclocking bolt head is NOT a problem - it is DESIGNED to - it's SUPPOSED to rotate at least 10 to 20 degrees past alignment with the bolt rib. IF it lines up tightly WITH the rib, then it is OUT of spec and NOT corect and potentially a problem.
Someone has fed you completely wrong information there my friend.
The Bolt head is supposed to clock in exactly with the rib when new, original armorers specs allowed for a small over clocking but only in wartime when resources were tight would they allow a 20 degree over clock situation without pulling the rifle from the line and sending it to be rectified by an armorer.




The entire design of the bolt is predicated upon the over-rotation of the bolt head so that the bolt does NOT lock up due to dirt ingress, misuse etc. It allows for problems to be ovecome.

You replaced something most likely NOT incorrect!!!
Why don't you read the Instructions to Armorers



(iii) Test the fit of the bolt-head in the bolt, and examine the face for erosion; when erosion is excessive or the rib turns beyond the rib of the bolt freely, fit a longer bolt-head and adjust to the 064 gauge as necessary.





Most people who do NOT know the SMLE have no idea about what is right and wrong.
If you actually believe that the bolt heads are supposed to be over clocked then you are describing yourself. I've never seen an Enfield owner make that mistake, much less go on to pontificate about it.
The amount that a worn bolt /bolthead combination could overclock before replacement was considered necessary increased only as resources for repairs could not keep up with demand.
The allowance was ten degrees for awhile the increased to twenty degrees, not because any degree of overclocking was considered desirable but rather that they could still judge the rifle as reasonably safe to fire with that much wear and not have to pull it from the line.

From much of the balderdash I've seen put forth as fact I'm fairly certain that unscrupulous sellers have worked to convince prospective buyers that the worn out actions of their rifles are as they should be. I've even come across a few that claim that a headspace of .084 is no reason for concern claiming that this was allowed in emergency situation when rifles were in short supply.
I've also personally seen a gunshop owner telling a customer that the loose bolt fit of an Enfield with visibly spread receiver walls was the normal condition, that all Enfields were that loose.
The Enfield boltway does have plenty of room, they even had to return many Australian Lithgows from the front because the Lithgow actions made before 1916 were too tight to operate in sandy conditions, but there is a limit to how worn or spread these can be before the action body is condemned.




The funniest I usually see in US publications is the magazine standing vertical in the triggerguard (so that the back of the mag does not lie flush against the bow) - I can GUARANTEE you'll get misfeeds doing that! It's not supposed to be vertical - it is supposed to be flush against the bow of the triggerguard, till the magazine snaps into place with a distinct audble click.
I've never seen an Enfield displayed in that condition in any gun publication in the US.

I have seen a TV news logo with an AR 15 with 30 round mag appearing to be inserted backwards, I'm pretty sure that was a photoshop error when they added an image of the dreaded Assault rifle magazine to a photo of an AR with standard 20 round mag for effect. Not all photographers know much if anything about rifles.

PS
Heres the Armorers instructions for examining the Bolt of the SMLE MkIII.



4. Action:—Bolt and bolt-head.
(i) Test the distance of the bolt from the end of the chamber with gauges .064-inch No. 1 and .074-
inch No. 1; the bolt should close over the .064, but not over the .074; when using the latter gauge, light
thumb-pressure only should be applied to the knob. Also test to see that the wing of the bolt-head does
not lift off the rib of the body.
(ii) Examine the bolt for fracture and damage, especially at the cocking cam and recoil shoulders.
Test the striker for free movement and fit in the cocking-piece: gauge the length and radius of the
striker point; examine the bents and condition of the cam stud of the cocking-piece.
(iii) Test the fit of the bolt-head in the bolt, and examine the face for erosion; when erosion is
excessive or the rib turns beyond the rib of the bolt freely, fit a longer bolt-head and adjust to the
064 gauge as necessary.
(iv) Examine the extractor at the hook and for fit on the screw, and test to see that the screw is
secure. Weigh the spring from the hook with the trigger tester - not less than 6 lb. and not more than 9
lb. should be required to move it.
Note.—The bolts of rifles in use should be completely stripped at each annual examination and
lubricated lightly with G.S. oil.

Heres the examination of the action body.



Body, etc.—Examine the body of No. 1 rifles for fracture, especially in the region of the recoil shoulders; test the charger guide bridge for security if oil exudes at the rivets, but no appreciable looseness is found, no action is necessary; test to see that the retaining spring is held rigidly by the sear screw. Examine the sear and magazine catch for condition and free movement, and oil, as required.
Gauge the protrusion of the stock bolt and see that the squared end is correctly located for the keeper plate in the fore-end.
Locking bolt and safety catch.—Examine for fracture and wear, and test for functioning in both cocked and fired positions of the rifle; see that the locking bolt spring is held firmly by the screw and that the screw is secured.

And heres a link to a PDF of the pamplet
http://www.owrpc.co.uk/Applications/1931.pdf

[Vulch]

Darn it, I better go tell the 3 unissued (as in NEW, never issued, unfired from proofing) Lithgow SMLE III*'s they are out of spec because all 3 of their bolt heads line up past the rib... damn it, better scrap them. Shame 2 of them are consecutively numbered. Oh, and the "Rifle, Experimental, Shortened and Lightened" also had it's bolt head go past the rib, and it most assuredly was never issued.

Same for the new just-unwrapped Fazakerley No4 Mk 2 of my friend we just unwrapped 2 weeks ago. Better condemn it as well.

I guess I just know nothing about Lee Enfields having collected them for 15 years. Damn it to he!!.

[PAT303]

Every Lee Enfield I've owned had the bolt head rotate passed the rib.Hollowpoint I'll have one of your No.3 boltheads mate,been looking for one for years. Pat

[Multigunner]

Darn it, I better go tell the 3 unissued (as in NEW, never issued, unfired from proofing) Lithgow SMLE III*'s they are out of spec because all 3 of their bolt heads line up past the rib... damn it, better scrap them. Shame 2 of them are consecutively numbered. Oh, and the "Rifle, Experimental, Shortened and Lightened" also had it's bolt head go past the rib, and it most assuredly was never issued.

Same for the new just-unwrapped Fazakerley No4 Mk 2 of my friend we just unwrapped 2 weeks ago. Better condemn it as well.

I guess I just know nothing about Lee Enfields having collected them for 15 years. Damn it to he!!.

Read the danged instructions to Armorers.
Those wouldn't be the first Lithgows I've seen that loosened up on first firing. I've seen a boatload of Lithgows that looked as pretty but overclocked by a quarter turn.

You have rifles that look mighty pretty but if the bolt heads over clocked by 20 degrees when they left the factory they were out of spec according to the Instructions for Armorers of 1931.

The Instructions for Armorers for the No.4 state that if the bolthead over clocks by more than 20 degrees the bolt head should be replaced.

The specifications loosened during WW2, but 20 degrees overclocking was not what the rifle was designed to do, it was the maximum wartime allowable overclocking before replacement was mandated.
My rifle was made long before 1931 and even longer before they loosened up the maximum allowable overclocking specifications.

Also you never bothered to ask how far my 1915 bolt head overclocked, you just made an assumption about a rifle you've never seen and proceeded to make judgements on a situation you don't truly understand.
If you've only collected Enfields for 15 years you haven't dealt with them as long as I have.

And as I suspected you appear to judge the condition of all these milsurp rifles by your experiance with safe queens you would hesitate to fire lest you lower their collector value.

If you have an Australian Army Armorers manual that instructs that a bolt head that lines up with the rib without over clocking should be turned to 10 degrees past the rib using the bolt head wrench I'd like to see it.

[Vulch]

Safe queens? Out of the 190 I had in the safes at one point, maybe 10 were safe queens. The rest were well used, and I needn't explain about the bolt heads...

10 to 20 degrees is HARDLY a quarter turn... more like JUST past TDC of the rib... but you knew that anyway. I am talking about the EDGE of the rib - the bottom edge - not the ENTIRE rib or the top edge. The head should JUST not quite line up.

I agree, if the rib of the bolt head turns past the entire bolt rib, you have TROUBLE. But, if it turns so that the rib of the head is a wee bit past LINING UP, it's CORRECT.

Most BSA's I had clocked up about 5 degrees over. Lithgow pre-WW2 the same. Lithgow and BSA WW2, 10 to 20 degrees.

Ishapore - who cares.

Armourer's found that is a bolt head clocked up EXACTLY in line with the bolt rib it was MORE likely to jam - they learnt that in WW1 in the mud of France. Post-WW1, they tightened up the specs again, yet as you have mentioned, come WW2, it was loosened again.

[bydand]

Well to start with, Bolt heads were fitted to each rifle. so while a No3 may have started out a certain length, it could be adjusted by the armourer. Only a NEW unfitted No3 will be the original size. Add to that, A new rifle off the assembly line could have anything from a O bolt head to a 1, or 2, Anything beyond a three is time for an overhaul

I trust Vulch FAR MORE than multigunner who I am starting to believe is also on www.jouster.com under another handle and noted for his overbearing attitude to anyone who dares to question his gospel.
Vulch has been collecting and shooting Enfield rifles for MANY YEARS. Although he went to the "dark side" for a while with mousers:lol:

But getting back to the subject, I have a No4Mk2 fresh out of the mummy wrap, and the bolt head does have a slight overtravel.

[Multigunner]

Safe queens? Out of the 190 I had in the safes at one point, maybe 10 were safe queens. The rest were well used, and I needn't explain about the bolt heads...

10 to 20 degrees is HARDLY a quarter turn... more like JUST past TDC of the rib... but you knew that anyway. I am talking about the EDGE of the rib - the bottom edge - not the ENTIRE rib or the top edge. The head should JUST not quite line up.
And those nice shiny FTR'ed Lithgows in that shipment all had bolt head over clock of a quarter turn, not a few degrees but around 90 degrees. I suspect these were damaged during proof firing prior to being imported, or had been used with unsuitable ammunition before being pulled due to damage and placed in storage till sold off. The lugs showed significant signs of upset as well.




I agree, if the rib of the bolt head turns past the entire bolt rib, you have TROUBLE. But, if it turns so that the rib of the head is a wee bit past LINING UP, it's CORRECT.

Most BSA's I had clocked up about 5 degrees over. Lithgow pre-WW2 the same. Lithgow and BSA WW2, 10 to 20 degrees.
I'll keep my WW1 era Enfield rifle in pre WW2 trim, not degrade it to suit WW2 specifications for a Lithgow. The replacement BSA bolt was from a batch made in 1956 to refurbish SMLE rifles of varied manufacturers and time periods, the matching Bolt Head was selected by the seller for best fit on this bolt body and clocks in perfectly.

You can expect any well used SMLE will have a few degrees of over clock, not because it left the factory in that condition but due to ordinary wear.




Ishapore - who cares.

Armourer's found that is a bolt head clocked up EXACTLY in line with the bolt rib it was MORE likely to jam - they learnt that in WW1 in the mud of France. Post-WW1, they tightened up the specs again, yet as you have mentioned, come WW2, it was loosened again.
A 20 degree difference would hardly reduce locking surface as much as the average bolt kick up, and would not prevent the bolt from closing far enough for the rifle to be fired.
Any slack in the fit of the bolt head does increase hammering of the mating shoulders of both bolt head and bolt body leading to a steady increase in wear.
The Bolts were expected to wear in, not wear out.

I'd still like to see an armorers manual that states that the bolt head should over turn by ten degrees much less 20 degrees straight from the factory.

From what I've heard Lithgow no longer manufactured the parts for these rifles, they assembled them from subcontractor supplied parts, contractors with no previous experiance in gunmaking. I also have reason to believe that late wartime rifles were made from a steel that was inferior to that used for pre WW2 rifles, a carbon steel rather than the Chrome Nickel Steel used for other manufacturers SMLE production.
The WW2 production Lithgows I've seen don't impress me a bit, the pre WW2 Lithgows look to be as good or better than contemporary BSA or Enfields.

Its not uncommon for a newbie Enfield owner to over clock his bolt head believing they were meant to be screwed down tight, they then visit forums to ask why they can't get their bolt back in the receiver. I've seen these sorts of first posts a number of times. It doesn't take much to loosen the bolt head threading by trying to screw it down tight. I expect thats a major cause of over clocking , careless recruits not following proper procedure when reassembling the bolt after cleaning and damaging the threads. I've also seen a friend do the same first time he tried cleaning his 1918 BSA, luckily I saw what he was doing and stopped him, but it resulted in about ten degrees over turn when there had been no visible overturn before.

The side play was far more of a concern to me, though over clocking that couldn't be reduced by other bolt heads I'd tried was reason enough to replace the bolt body. Headspace was fine at .068, the maximum commercial limit during the early 20th century and the measurement to be expected after proof testing and before wear increased it.
The Replacement bolt bodies and bolt heads are pre proofed and bear the proper markings.

[Multigunner]

I trust Vulch FAR MORE than multigunner who I am starting to believe is also on www.jouster.com under another handle and noted for his overbearing attitude to anyone who dares to question his gospel.
I couldn't care less who you put your faith in, facts are facts, read the manuals gun safety is not faith based.


Vulch has been collecting and shooting Enfield rifles for MANY YEARS.
And managed to do so without actually reading the manual.

Slight is an unscientific term, and I could care less about what I'd consider a "slight" overturn.
Huge Honking Over turn is a different matter.

I believe Vulch's own words disprove his earlier claim.


Originally Posted by Vulch
Errrr.....

Overclocking bolt head is NOT a problem - it is DESIGNED to - it's SUPPOSED to rotate at least 10 to 20 degrees past alignment with the bolt rib. IF it lines up tightly WITH the rib, then it is OUT of spec and NOT corect and potentially a problem.


Most BSA's I had clocked up about 5 degrees over. Lithgow pre-WW2 the same
So either the BSA and Lithgow rifles were not in spec at less than ten degrees over clock, or his original claim was wrong.
The Enfield bolt was not designed to be ten or more degrees off the money, normal wear could result in a creeping loosening of the thread fit over time.

[Dean D.]

Boys, keep it civil.

This thread has been very informative with lots of good stuff so far. If you cannot keep your comments civil I will wade in using the edit and delete key. No finger pointing or name calling, it is not in keeping with the spirit of our community here.

My Mother always told me when I was growing up; "If you can't say something nice, don't say anything at all". We should all listen to my Mother's advice.

[Multigunner]

Boys, keep it civil.

This thread has been very informative with lots of good stuff so far. If you cannot keep your comments civil I will wade in using the edit and delete key. No finger pointing or name calling, it is not in keeping with the spirit of our community here.

My Mother always told me when I was growing up; "If you can't say something nice, don't say anything at all". We should all listen to my Mother's advice.

Sounds cool to me.

[gew98]

And those nice shiny FTR'ed Lithgows in that shipment all had bolt head over clock of a quarter turn, not a few degrees but around 90 degrees. I suspect these were damaged during proof firing prior to being imported, or had been used with unsuitable ammunition before being pulled due to damage and placed in storage till sold off. The lugs showed significant signs of upset as well.

You do know that the VAST majority of Lithgow made SMLE's imported into the USA where John Jovino imports , of which good Old JJ assembled the vast majority stateside...and those guns have not the best quality fit & finish due to those loads of parts he assembled into rifles.
Lithgow made and assembled SMLE's have had the best reputation of them all for accuracy...right down to the Heavy barreled SMLE's they produced for serious iron & optical sight use.
The time I spent in the army where I had to deal with manual wonks always made me laugh. Those were the guys that only knew what they read or what they were instructed to read with little practical on hands experiance.
Which guy would you trust to work on your car...the guy writing repair manuals for 20 years or the guy having 20 years doing the actual repair work.... I know which one I'd choose from experiance since the manuals don't always do the "math" so to speak.

[Multigunner]

I'd choose a craftsman who read the manuals, shadetree gunsmithing is as dangerous as shadetree auto mechanics.

Now back to the topic of the Bolt heads.

Best resource on the Enfield threads.


The "Enfield Thread Form" appears not to be consistent, varying between different examples of threads per inch. The forms have been established as far as possible. This work was carried out by the MoD Pattern Room. At the moment there is no intention of publishing the forms, at least not until they have been established beyond reasonable doubt.

Not all the threads shown below are "Enfield". With the SMLE Mark VI, came the use of "British Association" threads or BA as they are known. Although now obsolete, tooling for BA threads can still be obtained. Some threads on Enfield rifles are in fact Whitworth form, ie. BSW and BSF.



http://freespace.virgin.net/j.franklin/toys/thread-table.htm

If the thread pattern of the bolt head shank doesn't match the thread pattern of the bolt body then excessive wear will result.

Unlike a screw or bolt screwed down tightly and meant simply to hold something in place, the threaded shank of the bolt head is intended to move freely back and forth as the bolt is rotated into or out of battery. The threaded shank is a bearing surface and so is the internally threaded surface of the bolt body.

[gew98]

A guy whom writes the manuals and never hit a lick of it with his hands is a "craftsman" ?. Have you ever worked with a book smart fellow like that doing heavy mechanical work ?. I have with more than a few and to a man they could talk the talk..but hand them the tools of the trade and they could'nt even sqaure a bracket let alone plum a rail. I've had prints so way off that in talking to the "engineer" he insisted it was so as written. Got him in th efield and lo and behold.... he had to not only eat crow he could'nt figure out how to rectify his booksmart blockage...I had to do it for him. The real world is far off different from a guy behind a desk "writing manuals".

[303Guy]

I started making a bolt head from a piece of 41-40. The only trick I could see was to get the thread start in the right place to which end I was going to thrad the 'blank before cutting away the exess material. Cutting away the exess material would have been the hardest part.

[HollowPoint]

At present, I have three different Bolt-Heads and all of them will screw into my existing bolt easy enough; and with about the same feel and turn beyond top-dead-center so I take it the thread pattern is correct for what I need.

I didn't realize that asking a couple of questions would ignite such a difference of opinions. Kind of makes me glad I'm ignorant when it comes to Lee Enfield specifics.

Is there a way that a guy can measure for himself, the thread pitch and threads per inch just to make sure I'll be applying the correct threading?

If the threads act as a type of "bearing surface," then it sounds like I'll have to make sure to make them fit just this side of being snug. From there they can "wear in."

HollowPoint

[PAT303]

I think allot of the issue's with Lee Enfields comes from people who read up on how it should be done ignoring the fact that both Australian/British riflemen have used these rifle since day dot and gunsmiths from both countries have put in countless hours work to get them shooting to a very high standard by doing things outside the boundries imposed by manuals.There is an awfull lot of very skilled knowledgeable smiths in Australia that can and do get Lee Enfields shooting to a standard well above the norm and it was target rifle smiths who got the first really effective sharpshooter models of the LE out on the battlefield.Lastly a very effective way to shorten an LE's headspace is to hard chrome the bolt face,you can go as thick as .020 and then polish it back too the desired thickness,a popular and easy job. Pat

[Multigunner]

I think allot of the issue's with Lee Enfields comes from people who read up on how it should be done ignoring the fact that both Australian/British riflemen have used these rifle since day dot and gunsmiths from both countries have put in countless hours work to get them shooting to a very high standard by doing things outside the boundries imposed by manuals.There is an awfull lot of very skilled knowledgeable smiths in Australia that can and do get Lee Enfields shooting to a standard well above the norm and it was target rifle smiths who got the first really effective sharpshooter models of the LE out on the battlefield.Lastly a very effective way to shorten an LE's headspace is to hard chrome the bolt face,you can go as thick as .020 and then polish it back too the desired thickness,a popular and easy job. Pat

Theres a type of plating I'd considered trying out to restore the threads of worn bolt heads, the process is already used for similar purposes.



Due to the high hardness of the coating it can be used to salvage worn parts. Coatings of 25 to 100 micrometres can be applied and machined back to final dimensions. Its uniform deposition profile mean it can be applied to complex components not readily suited to other hard wearing coatings like hard chromium.
http://en.wikipedia.org/wiki/Electroless_nickel_plating

The armorers manuals were the result of decades of hands on experiance by qualified authorities. Many of those authorities were combat veterans rather than pencil pushers.

Several contemporary publications on the Enfield by both military and civilian authors, draw on information supplied by the very men responsible for the development of both the rifle and the .303 ammunition it fired.

Loose headspace is okay when cartridge cases are manufactured with this in mind, but only up to a point. Execessive side play is never a good thing and is noted as a common cause of failure to eject, as well as leaving a path for shearing forces.

Since almost every incident of injury or death due to a failure of an Enfield action is the result of broken, shattered, or sheared bolt heads, I take the qualty and fit of the bolt head very seriously, just as the British military did.

The argument about over clocking was due to the statement that the Enfield bolt head was designed to be loose fresh from the factory rather than becoming worn and loosened over time due to firing many thousands of rounds and ham handed reassembly by generations of recruits.
I've still seen no manual entry or armorers notes that instruct that a bolt head that clocks in with no overturn should be deliberately overclocked by ten degrees much less twenty.

Allowable headspace figures of .074 before the bolt head or bolt body or both should be replaced are not to be taken as that being the optimal headspace. When the rifle has a headspace of .074 its a sign that it has become worn, but not so worn as to call for rectification just yet.
So long as the bolt closed easily on a .064 gauge it was good to go, most .303 rims of the day, both military and sporting, were thinner than that, .064 being the design maximum acceptable rim thickness.

Despite some contary opinions, head space does affect accuracy. When the Krag was in development they tested the effects of headspace from a .002 head clearance with the test cartridges to .006 clearance and possibly larger. It was found that a head gap of .004 was optimal for accuracy, accuracy was actually lessened by a .002 headgap.
The cartridge drawings of the Krag indicated a .064 rim, but the Manuals give the expected .060 as the rim thickness.
Commercially produced cartridges with rims as thick as .068 were prized by handloaders and target shooters.
I suspect this was in part due to target shooters lapping the locking lug till the safety lug made contact to improve lock up. That and the incidents of lug setback when the higher velocity Krag ammo was introduced and found to be a tad too hot for the average Krag action.
I've read of Australian shooters examining .303 collections of once fired reloadable cases and saving those with rims of .068 for handloading and target shooting.

The Lithgow was originally manufactured using the highest quality machinery built specifically for the purpose by Pratt & Whitney in the US and shipped to Australia after a short trial run to train key personel.
I've never seen any reason to doubt the quality of the pre WW2 Lithgow rifles.

When the surplus rifles were imported here most were of decent quality, but many were not.
Before 1916 the Lithgow boltway was manufactured at the minimum clearance figure and the body body diameter was manufactured to the gauge at the maximum allowable diameter. These were the only SMLE rifles that showed a tendency to become jammed by dust and sand during WW1 fighting in the Dardanelles campaign . The rifles at the front were loosened up by armorers and put back in service quickly, while those not yet shipped had the clearances increased before shipping.

The AIA site states that the common overturn for a No.4 rifle was 7.5 degrees, not ten or twenty. AIA tries for no more than a one degree overturn for their match rifles.

Bolt body diameter is an other area often over looked, since the bolt has significant clearance when new allowing some tilt under hand pressure when cycling the bolt. I've run across a few with little side clearance but with vertical play enough that the bolt head contacts the lefthand feed lip of the magazine wearing a flat spot, and a few magazines with lefthand lip partly torn away. The leverage of the hand on the bolt handle cants front of the bolt down and to the left, there being little or no wear on the right side. If present at all wear to the surface of the bolt body would be confined to the rear and right of the rib and directly behind the guide rib locking lug surface.
Bolt bodies slightly larger in diameter than a worn bolt body could be used to take up some of that slack.

plating the inside surfaces of the bolt way might improve the fit, and reduce further wear.

Since my target shooting doesn't involve crawling through mud I'm completey satisfied with a precisely fitted bolt head and bolt body that doesn't noticably rock when cycling.

[Vulch]

Sam,

When I "quoted" 10 to 20 degrees, I was not measuring it with a dial calliper or a protractor - I was making a WAG. 7.5 degrees does sound about right. It's not much anyway.

If a SMLE will headspace correctly with the bolt head, does it matter how far past the bolt rib the bolt head goes when it is NOT being fired? The bolt raceway rib stops the head rotating past the line of the rib anyway (the head can only turn FORWARD when in the action, tightening headspace, NOT increasing it - unless they made a reverse threaded bolt head and bolt body for you :) ), and the threads (unless damaged) also prevent setback of the head, so, so long as it is of proper headspace WHEN IN BATTERY, it does not really matter how far past TDC the bolt head clocks "on the slack".

AIA rifles are hardly battle rifles. AIA isn't churning them out fast to help against the Japanese...


Your assumptions on Lithgow are also VERY VERY flawed.

I'd also like to see your references for "Since almost every incident of injury or death due to a failure of an Enfield action is the result of broken, shattered, or sheared bolt heads" - please cite the injuries and deaths, as well as cases of sheared bolt heads.

[Multigunner]

(the head can only turn FORWARD when in the action, tightening headspace, NOT increasing it -
When you turn the bolt into battery the the bolt head screws up tight to the bolt drawing back from the casehead, not the other way around. when you open the bolt the bolt head unscrews by the number of degrees of bolt rotation.
How tight the bolt head screws up against the mating shoulder of the bolt body depends on how closely fitted it is to begin with.

You can find the majority of easily available recorded cases in the records of the House of Commons of Canada, I think its in the 1908 edition as part of the Ross Rifle debates.
The death of a hunter is recounted by a John Crosman who was asked to examine the rifle to determine the cause of the accident, thats in a Gun digest I still have a 1981 35 year aniversery edition. Crosman wrote in this article on recalls that the incident had happened more than a dozen years earlier so that would have been before 1969.

Since I'm not a medical examiner I don't have access to all the records of firearms accidents in England and Cananda, so these will have to do.

Theres at least one case of the entire right rear sidewall breaking away maiming a British sargent. The case came up in the British Parlement when it was decided to grant him and his family funds to cover their expenses till he could return to duty.
Those incidents in Canada included one death and a rather hideous injury that the victim survived.
The incidents in Canada involved rifles in good condition and freshly manufactured milspec ammunition on rifle ranges.
The incident Crosman wrote of involved a well worn rifle and fresh Federal sporting ammunition, Crosmans verdict was that bore condition caused the accident, but Federal voluntarily recalled their .303 ammo anyway and adjusted the load to make allowances for corroded bores.

Only the maimed sgt is named in the official records, it was not considered proper to list the victims by name during the Ross debates. They had a certain respectbfor privacy in those days.
A injured Range officer may be mentioned by name. A "man of the northwest territory" is mentioned as having been killed.
There is a detailed list of dozens of action and barrel failures in a two year period.

I think it was P O Ackley who ran an experiment on the progression of degradation of an Enfield action when testing an Improved case .303 wildcat with increasingly powerful loads. As expected the bolt heads go first after increases in headspace.

A range officer posted of a blown bolt head incident he witnessed perhaps two years ago, I think it was at Bisley but I'm not sure. A young woman bystander was hit in the neck by shards but not badly injured.

[Multigunner]

At present, I have three different Bolt-Heads and all of them will screw into my existing bolt easy enough; and with about the same feel and turn beyond top-dead-center so I take it the thread pattern is correct for what I need.

I didn't realize that asking a couple of questions would ignite such a difference of opinions. Kind of makes me glad I'm ignorant when it comes to Lee Enfield specifics.

Is there a way that a guy can measure for himself, the thread pitch and threads per inch just to make sure I'll be applying the correct threading?

If the threads act as a type of "bearing surface," then it sounds like I'll have to make sure to make them fit just this side of being snug. From there they can "wear in."

HollowPoint

You can make a Cerosafe casting of the threads then carefully unscrew the casting and measure the impression of the threads.

Theres conflicting information on the Enfields, partly due to changes in specification and variation among manufacturers, and in large part because the British Ministry of Defence destroyed almost all the records on development during the 1950's. Lord cottesloe called it a "slaughter" in his forward to Reynolds book of the Lee Enfield.
Reynolds for the most part had to rely on bits and pieces found in personal files of a number of officers who had saved copies as part of their work and on his own memories.

Theres also a lot of glamorised bull and folks finding excuses why their own rifles have such loose bolts and headspace by claiming they were made that way.
Any rifle that spent decades in service will show some wear. Worn rifles run through a hurried FTR and wrapped with little expectation of ever being issued again turn out not to be as new in fact as in appearance.
A gunsmith on another forum had a fresh from the mummy wrap No.4 blow its bolthead on the first shot. Luckily he test fires every rifle remotely in a firing booth so no one was hurt.
I test fire every rifle I get remotely, even brand new rifles. No sense taking chances, or depending on the workmanship of some overworked assustant armorer of fifty plus years ago much less some unknown third world grease monkey with a bolt head spanner.

[Vulch]

When you turn the bolt into battery the the bolt head screws up tight to the bolt drawing back from the casehead, not the other way around. when you open the bolt the bolt head unscrews by the number of degrees of bolt rotation.
How tight the bolt head screws up against the mating shoulder of the bolt body depends on how closely fitted it is to begin with.



I guess I wrote it poorly - I meant that seeing the bolt head is locked into the action guide rib, when the bolt is cammed open, the bolt head runs FORWARD on the bolt (unscrews by almost 90 degrees), technically decreasing headspace (though of no importance). The only time headspace is DECREASED is when the bolt is turned down to battery - and thuis this is why headspace is measured with the bolt in the battery/closed position.

Now, when in battery, unless the guide rib is damaged, the bolt head cannot further rotate in either direction, more importantly, cannot rotate further ONTO the bolt body and therefore, simply, overclocking is not so much an issue so long as the bolt head spaces properly (we are not talking having bolt head threads exposed!). Relying on the threads of the bolt head alone is not overly wise, as the Lee Enfield system relies on the threads AND the bolt head body abutting the bolt body front face and contact with the threads. SOME commercial rifles have tried adjustable headspace with screw on adjustable bolt heads (or in Savage case, allowing the barrel to be reset as required)

That of course is "theoretical", but armourer's DID know what was safe and what was not.

I would hazard a guess that EASILY 85% of SMLE's I have seen and owned exhibited bolt heads turning past TDC (and I never measured the amount, so don't quote 10* to 20*). And all the ones I had I checked headspace, and all passed.

[Vulch]

You can make a Cerosafe casting of the threads then carefully unscrew the casting and measure the impression of the threads.

Theres conflicting information on the Enfields, partly due to changes in specification and variation among manufacturers, and in large part because the British Ministry of Defence destroyed almost all the records on development during the 1950's. Lord cottesloe called it a "slaughter" in his forward to Reynolds book of the Lee Enfield.
Reynolds for the most part had to rely on bits and pieces found in personal files of a number of officers who had saved copies as part of their work and on his own memories.

Theres also a lot of glamorised bull and folks finding excuses why their own rifles have such loose bolts and headspace by claiming they were made that way.
Any rifle that spent decades in service will show some wear. Worn rifles run through a hurried FTR and wrapped with little expectation of ever being issued again turn out not to be as new in fact as in appearance.
A gunsmith on another forum had a fresh from the mummy wrap No.4 blow its bolthead on the first shot. Luckily he test fires every rifle remotely in a firing booth so no one was hurt.
I test fire every rifle I get remotely, even brand new rifles. No sense taking chances, or depending on the workmanship of some overworked assustant armorer of fifty plus years ago much less some unknown third world grease monkey with a bolt head spanner.

I would not rely on Reynolds too much - there is a LOT of bad information in it, and a lot of VERY VERY outdated assumptions and flat-out incorrectness (his glaring examples are the heavy barrel Lithgows and the No5 "fakes" with metal nosecaps which we all KNOW to be GENUINE) They are just for starters. I no longer have my copy, as I found it rather humourous and useless in many ways (it is FAR from an epic biblical tome! Then again, no work on the Lee Enfield is, though the latest "The Lee Enfield" is getting darned good)

Most of the information supposedly lost (claimed lost) actually wasn't, and was well documented in Australia, New Zealand and Canada, where most of the recent research comes from now. Brits weren't the only ones keeping records.

[gew98]

Lewis , you put out too much common sense...but the manuals triumph for the "learned" it seems. The editing and deletion of posts don't help either.
Funny thing is I have yet to come across any Lee Enfield that could not be made right and shoot. Whilst rifles like the 1903 spngfld ... well they more often than not need to be scrapped. Says alot about them right there. The 03 and the Ross rifle are of the same cloth but at least the canadians took note and ditched their pariah.
As a sidenote it is amazing that the OP can or will likley be able to make an Enfield bolt head. I don't know another rifle action so versatile to be able to do such.. can't make a mauser type bolt and in a mauser if there is a headspace issue it's either a worn chamber shoulder which would require rebarrel , or lug setback...scrap the receiver time.
Love to see the finished product .

[Gtek]

Do you know the difference between a pig and an engineer? You can argue with a pig! I am an old fat barrel target guy, but on a #4 could you not remove barrel cut back shoulder, chase extractor cut, min. head and re-cut chamber? Would be a lot less arguing. Gtek

[gew98]

Gtek ; Years ago I had that done to a No4 mismatch action I was given. The job really was two fold as the barrel got cut down , rethreaded and bored out to 44 cal and then rechambered for 44 mag. 20 years ago the whole deal and winding up with a 18" barreled sort of No4 looking carbine in 44 mag cost me a wopping $170 for a smithy to do. I eventually traded it to a buddy whom sacrificed a desert eagle magazine modifying it to the No4 magazine body. Worked and looked great.
On the other hand a set of chamber reamers would likely drive the cost too high if the OP did it himself.
I like the pig & engineer anaolgy...so true so true.

[Multigunner]

I guess I wrote it poorly - I meant that seeing the bolt head is locked into the action guide rib, when the bolt is cammed open, the bolt head runs FORWARD on the bolt (unscrews by almost 90 degrees), technically decreasing headspace (though of no importance). The only time headspace is DECREASED is when the bolt is turned down to battery - and thuis this is why headspace is measured with the bolt in the battery/closed position.
I think the bolt rotation of the Lee Enfield is a good deal less than 90 degrees but I forget the exact figure, either just above or just below 80 degrees I think.




Now, when in battery, unless the guide rib is damaged, the bolt head cannot further rotate in either direction, more importantly, cannot rotate further ONTO the bolt body and therefore, simply, overclocking is not so much an issue so long as the bolt head spaces properly
I told you earlier that headspace was not a problem with my old bolt and bolt head, it was looseness of the threads with uneven wear that allowed excessive side play.

Others I checked with have found that the combination of the Early SMLE bolt head with a later production MkIII bolt body can lead to excessive wear. Some have checked the Notched bolt head taken from a worn MkIII body and found these would only screw into a unworn bolt body for 1/3 of the length of the shank before meeting great resistence. To screw the bolt head in further would have wallowed out the threads ruining the body for use with the proper MkIII type bolt head. This is what the situation was with mine.




we are not talking having bolt head threads exposed!). Relying on the threads of the bolt head alone is not overly wise, as the Lee Enfield system relies on the threads AND the bolt head body abutting the bolt body front face and contact with the threads. SOME commercial rifles have tried adjustable headspace with screw on adjustable bolt heads (or in Savage case, allowing the barrel to be reset as required)

That of course is "theoretical", but armourer's DID know what was safe and what was not.
The maximum allowable safe condition is a long way from optimal condition, and excessive sideplay was considered as good a reason for replacing the necessary parts as was excessive headspace. Excessive side play reduces the effective spring pressure of the extractor against the inside of the clearance cut. This allows the bolt to spring up faster and farther during bolt kick up. Wear to the bolt body behind the guide rib lug exacerbates that situation.
Sideplay also is a major cause of failure to eject by limiting the amount of sideways force applied to the fired case during the ejection cycle. If the case rim does not contact the inner left side wall with enough friction to pop it out of the grip of the extractor then it will usually fall back into the action when contacting the ejector screw which would normally eject a unfired case with ease.




I would hazard a guess that EASILY 85% of SMLE's I have seen and owned exhibited bolt heads turning past TDC (and I never measured the amount, so don't quote 10* to 20*). And all the ones I had I checked headspace, and all passed.
Thats an advantage of living in a country where they had warehouses full of unissued spare parts and many unissued rifles sold off cheap to locals, a many veteran former armorers who became gunsmiths who specialized in repairing Enfields.
Considering the loose headspace allowance for the Enfield I'm not suprized, and I'd be even more suprized if a gunsmith worth his salt who specialized in the Enfield would let one leave his shop with bad headspace or excessive sideplay.

But many in Australia have posted to other boards about their aquisitions, and believe it or not not every Lithgow in the country has remained in prime condition or been within a mile of a gunsmith since Moses was a pup.

Theres also the color coded cadet rifles to consider.
Green paint meant safe to fire, Yellow meant degraded but still safe, Red meant if you love your momma and don't want to make her cry please don't pull the trigger on a live round.
Some like to collect these, not intending to ever fire them. Some never knew what the red paint meant and cleaned the stock, now they have a rifle any armorer would condem and don't know it.

The discussion has become more civil without the hoity toity putting on of airs and the admission that even a collector with a big stable will throw AWAG that turned out to be a gross exageration out as solid fact.

PS
When fired the collar of the firing pin will make contact with the base of the bolt head shank, that being what limits firing pin protrusion. The looser the headspace the less the striker impact is cushioned by the primer. When the collar contacts the bolt head shank, any looseness in the fit of bolt head to bolt body will allow the boltface to be pushed closer to the case head.
This would leave a temporary gap between the mating shoulders of bolt head and bolt body. The bolt head is then forced violently against the bolt body by the expansion of the case, the looser the headspace and wider the gap the more momentum to that movement. The load bearing shoulders are then progressively battered with each shot, and the threads loosened even more.

With a 20 degree allowance before rectification for the Canadian No.4 its no wonder they ran short of Long Branch rifles and now have to buy Pakistan Ordnance Factory No.4 rifles for their Rangers.

[Multigunner]

Do you know the difference between a pig and an engineer? You can argue with a pig! I am an old fat barrel target guy, but on a #4 could you not remove barrel cut back shoulder, chase extractor cut, min. head and re-cut chamber? Would be a lot less arguing. Gtek

Setting back an Enfield barrel was actually a fairly common gunsmith alteration in both Austraila and suprizingly in France.

French gun laws allowed civilians to own military rifles only if it could not chamber a military cartridge still in use.
The collectors got around this by having the barrel set back to shorten the chamber to 54 mm and a ".303 Sporting" cartridge identical to the .303 British other than case length and position of the shoulder was developed.

A Similar cartridge called the 7.7X54R was developed in Australia, and besides the set back Enfields it was also used in a single shot conversion of the FN FAL.

The limited ban on military cartridges in some districts of australia was not nationwide and near as I can tell lasted for only a short time.

[Vulch]

Sam,
A WAG was all you were going to get - some of us do not have the "anality"to be bothered to precisely measure how much past-TDC a bolt head rotates. I could measure it, and it would be meaningless, because simply the rifles all headspace correctly, exhibit limited sideplay, have straight raceways and guide ribs, and shoot fantastically. Most have their original bolt heads, none show wear in the lugs or setback in the raceways or locking recess.

I never mentioned sideplay previously. Sideplay is a sure indication of more likely an ACTION problem than a bolt problem. Have you used the action straightness jig to check your action? Have you measured the distance between the left and right rear action sidewalls/raceways? Have you checked the integrity of the guide rib? Have you checked the guiderib wear near the front end? have you checked the extractor cut for defects?

Now, you mention the early notched bolt head in the later bolt body. Considering that notched bolt heads (with corresponding firing pin with lug on the collar to facilitate removal for cleaning) were withdrawn from field use in WW1, and MOST WW1 production did away with it EARLY ON - simply because it was thought ill advised to allow a regular soldier to totally strip a bolt for cleaning. The new designed firing pin and bolt head of course do not have this feature, and it was slightly altered such that - as you have found - an earlier notched head will NOT fit the body without effort.

So, who was using a notched bolt head? This was never mentioned previously - and if your BSA had the notched bolt head, it was most assuredly a replacement with an earlier part. I do NOT have a copy of List Of Changes anymore, but I believe the change in bolt heads and firing pins was officially promulgated in 1914, maybe 1915. Most of these early bolt heads were to be removed and stored as "emergency spares" or simply destroyed. Any rifles that came in for repair had these removed and changed.

In my years of collecting, only 3 SMLE III's had this feature original to them - and all of them were Police issue SMLE III's (that did not get military armourer attention per se)

Additionally, I have had new replacement bolt bodies that simply will NOT fit an action - too LITTLE sideplay. I have had to re-head only 1 rifle in all my years, and that was a 1918 BSA. I had to try 7 different bolt heads, because most simply would NOT clock properly AT ALL - most UNDER clocked significantly. And as you know, British made SMLE's had pretty random interchageability, whereas Lithgows have the best (better machinery, thanks P&W!)

Gunsmiths around every corner here... geez, I wish! I know of 6. That's within a 200 mile radius.

[Vulch]

Setting back an Enfield barrel was actually a fairly common gunsmith alteration in both Austraila and suprizingly in France.

French gun laws allowed civilians to own military rifles only if it could not chamber a military cartridge still in use.

Partially correct. French Law permits rifles in ORIGINAL calibre under certain number limitations, if to be used in matches etc.


The collectors got around this by having the barrel set back to shorten the chamber to 54 mm and a ".303 Sporting" cartridge identical to the .303 British other than case length and position of the shoulder was developed.

A Similar cartridge called the 7.7X54R was developed in Australia, and besides the set back Enfields it was also used in a single shot conversion of the FN FAL.

I would hardly call the Lithgow single shot target rifle a conversion of the FN FAL (we call the semi-auto military rifle an SLR, NOT FN FAL). The single shot rifle bears VERY little parts from the SLR. It's more a new made rifle than a conversion. I take it you have never fired or disassembled one?



The limited ban on military cartridges in some districts of australia was not nationwide and near as I can tell lasted for only a short time.

Thankfully. When you see a No6 or a SMLE III* HT done to 7.7x54R, it makes you cry. I have seen BOTH!

[Multigunner]

I never mentioned sideplay previously. Sideplay is a sure indication of more likely an ACTION problem than a bolt problem.
Gee as if I couldn't tell the difference after examining the bolt head and confirming that it was the fit of the bolt head itself that was the problem.
When you hold the bolt in your hand and can see the sideways movement theres no mistaking it.

There is no excessive wear to the insides of the bolt way directly to either side, just the slightest at the points I mentioned earlier ,and the fit of the guide rib to the guide rib slot is very good, and no amount of slack between guide rib and its track would have had any effect on movement of the bolt head or bolt body when the bolt has been rotated into battery.

Theres very little contact surface between the bottom of the bolt and the receiver because if the cocking piece track and the opening of the left locking recess. Theres only about a 1/4 inch wide section directly in front of the opening, so any wear there reduces sopport for the bolt body as it moves forawards. Theres no positive support from the lefthand side wall ahead of the charger bridge because of the angled channels and nothing but the leverahe of the hand on the bolt knob to push the bolt body towards it. The bolt head guide rib contacts only the bolt head, it exerts no guidance on the bolt body itself amd does little to limit horizontal movement of the bolt head for that matter.



The single shot rifle bears VERY little parts from the SLR. It's more a new made rifle than a conversion. I take it you have never fired or disassembled one?
No reason to expect that I would have. Photos I've seen do show that theres little remaining of the FAL/SLR in that rifle.

Since theres no longer a real purpose for the 7.7x54r I would hazzard a guess that these are collectors items of some interest.



When you see a No6 or a SMLE III* HT done to 7.7x54R, it makes you cry. I have seen BOTH!
All part of the history of the rifle, and likely a rare modification.
A good possibility that having been a target or competition rifle the setting back and cleaning up chamber and throat may have given those rifles a new lease on life. It was common for U S target shooters to set back a barrel that had an eroded throat and freshen the chamber, many of Harry Popes barrels were set back many times.
When single base or low nitro double base powders are used wear tapers giving a microscopic choke effect that reduces blow by and makes for more consistent velocities. The grip of the lands on the bullet increases on the way down the bore.
Many shooters prefered a slightly worn barrel to a new barrel that required breaking in. Springfield barrels steadily improved in accuracy for the first 1500 rnds, then continued to improve slightly to and 300 or more, accuracy leveled off till between 4500 and 5000. Barrels were usually replaced at the 5-6000 mark but could hold good groups at 600 yards for up to 18,000 rounds.

Bore life depends greatly on bore to bullet fit , the great variations in Enfield bore sizes meant some lasted far longer than others, but quality of ammunition remains a wild card. Milsurp with undersized bullets might shoot great in one rifle and keyhole every shot in another made on the same day and with the same round count.
The use of Wire Gauze in cleaning wrecked more barrels than any number of rounds could have.
Which reminds me, John Crosman stated that the chamber of the rifle who's bolt head blew out was thinned on the right side, by which I think he meant worn out of the round. I've seen [lenty of cord worn muzzles but happily no cord worn chambers as of yet.
The lack of support caused the cartridge case to blow out sending hot gas directly into the extractor lug slot, A chunk of the extractor lug with extractor still attached severed an artery and the hunter bled out in minutes before anything could be done to save him. Since the Enfield .303 chamber is tapered, and the cartridge case body is tapered more than with most military cartridge designs, loose headspace gives the same effect as an oversized chamber. When that already generous chamber becomes worn theres less and less support for the case walls.
If out of the round as well a blown case can happen.

Loose fitting bolt heads that shift to one side might also result in more pressure on one side of the shoulders than the other if theres any tilt.



So, who was using a notched bolt head? This was never mentioned previously - and if your BSA had the notched bolt head, it was most assuredly a replacement with an earlier part. I do NOT have a copy of List Of Changes anymore, but I believe the change in bolt heads and firing pins was officially promulgated in 1914, maybe 1915. Most of these early bolt heads were to be removed and stored as "emergency spares" or simply destroyed. Any rifles that came in for repair had these removed and changed.

Its the same bolthead that was on it when the previous owner bought it. After the warped fore end that was on it was cut down the rifle proved extremely accurate. I had him leave the nose cap and other fitting with me and promise not to sell the rifle to anyone but me, as I wanted to restore it with a new fore end.
The fore end that had been on it was itself a new condition replacement, but of very poor quality wood and the worst warped fore end I've ever seen.

The wood was very odd, bone white and so flexible you could flex it by hand as if it were one tenth the thickness. The fore end took a nose dive ahead of the sling band and when the nose cap was on there was a visible bow between band and nose cap.
With that fore end on it you could have thrown it with more accuracy than you could have shot with it.

The rifle appeared to have been dolled up just enough to be sold without much if any attention paid to details.
The Rifle is an Enfield Lock product dated 1915 , a MkIII marked body with no * and no sign it ever had one. The replacement bolt body is a BSA manufactured in 1956 from the batch number. BSA contracted to refurb SMLE rifles for foreign contracts such as the Austrian Police rifles in use for some time there before they modernized. Odd to think of Austrians using SMLE rifles, especially during the Cold War years but many have shown up in collections.

I suspect that when they fixed this rifle up to sell off they found the bolt body threads already worn and used the mismatched threads of the Notched bolt head to achieve what would be a tight fit , but only temporarily. After a few years of light use the mismacthed parts both wore unevenly.
When my friend first got the rifle everything seemed fine. Since he lost a thumb in a workplace accident and could no longer work the safety with his sgooting hand he decided it was time to sell the rifle to me.

The Rifle is now as good a shooter as before the bolt head loosened up. The fore end is of the type used on rebuilds of the 1920's. I'd have prefered a proper MkIII fore end with volley sights. I put a new old stock cut off plate on it, and replaced its broken windage adjustable rear sight.
The rifle is in much the same trim as a civilian owned surplus SMLE target rifle of the between war years. The bolt is a later production but would be about the same as a BSA bolt used to upgrade a civilian target rifle in those days.
I haven't mounted the PH5A yet, I don't get much opportunity to do any serious shooting these days so that can wait till I've explored the limits of the rifles accuracy with the open sight.

The old bolt body is almost certainly not the original even though the numbers matched. renumbering of rifles and parts appears to have been a common practice.


PS
If anyone is interested in these BSA replacement bolts heres what I can tell you about them.

These bolts are finished and blued except for the lug faces and a short portion directly behind each lug.
The lugs must be hand stoned to match the slight rake of the mating surfaces of the action body.
But before you start you must make sure the unfinished area behind the lugs allows the bolt to turn freely into battery. Theres several thousands, more really, of extra metal there. This area should be carefully stoned till the bolt can be rotated home without excessive force. A good tight fit there when in battery braces the bolt body so lug contact is not thrown off by the pressure of the extractor spring.

Preliminary fitting can be done with bolt head removed but firing pin and spring left in place. The cocked striker will provide a steady and properly centered push against the lugs and locking recesses.
Smoking the lugs to judge contact works up to a point, but I prefer to use cold blue. By rotating with spring pressure any high spots will show as bright spots.

While stoning is the term, and stones were once used, I have a set of super hard needle files given me by a robotics engineers, these are hard enough to cut a regular file and the cut is as fine as most whet rocks. The files are easier to control than a stone.

I don't know the exact procedure used at the arsenal but the common method for fitting lugs is to insure equal contact with at least 80% of the lug being in full contact before test firing.

At the factories they used two proof charges for the asembled barreled action. One was dry and one oiled. The proof charges also served to iron out any high spots on the lug surfaces, called setting the lugs.

The replacement bolts bear a BNP proof mark so these must have been proofed using an action body meant for the purpose. The condition of the bolt body and its unfinished and unfitted lugs precludes these having been proofed in a regular rifle action, they simply wouldn't fit.

[gew98]

Setting back an Enfield barrel was actually a fairly common gunsmith alteration in both Austraila and suprizingly in France.

French gun laws allowed civilians to own military rifles only if it could not chamber a military cartridge still in use.
.

Ah multitude... technically wrong as it is "military calibers and not "what they can chamber". You can in france and as is often doen have an 8x57 chamber reamed to 8x60 and the 8x57 chambers and goes boom. They do it all day long.
The french laws basically state any military chambering used by the french military , and that they used many is no small statement. But there are subtle ways around it. Sadly the worst part is all the 'extra' stamps from proofing unde rthe regs that get added to such arms . But that's the glory of socialism and a government that has not mechanism to be stopeed from limiting peoples ...well they don't have a 2nd so it's not exactly rights.... but peoples ability to own things they may use against a tyrannical government. Sort of reminds me of how east germany when it existed took ungodly rare mauser rifles and had them deactivated by the score...because the state had fear , of the people.

[gew98]

Gee


All part of the history of the rifle,

.

You are a fountain of useless manual knowledge . In all my years of shooting I have never once seen an enfield action fail...yet have been accustomed to your glorious 03 failing more than once , injuring and or killing users of that substandard product. As the "I chord" committe pointed out in the investigations of how the M16 was dumbed down when produced/supplied to the US Gov't to include the substandard ammo suppplied at the same time...some bigwigs should have hanged for that !. Same kind of lot that should have hanged for the 1903 and the M14 !. But government rarely holds those kind of sods accountable for the deaths of their countrymen by such substandard equipment. It gets fixed..well some like the '03 get sugar coated and they move on over the casualties.
The treatises' you plagarize from manuals/books written about the enfiled rifle and ammunition are all very well known to collectors and shooters like myself that own these books which makes you come across like a pontificatory sod hell bent on bureacracy by the numbers and not hands on real world doings. You add nothing to this discussion by repeating these in engineerishly cloaked speak....when grunts like myself and vulch have and do use/collect these arms regularly and have considerable initmate hands on bang bang knowledge of them outside of the biblical manual mindset.
I have had more mausers and 03's with bulged brass indicating serious tolerance deficiancies than hardly any enfields I have owned and or shot. The only time I have ever seen an enfield that needed a bolt head swap was on a rifle with a mismatch bolt. And when you come across the godlike 03 with bad headspace and or chamber dimensions..time to rebarrel or look close for lug setback in the receiver..as long as it's not the class c steel grenade to the head heat treat , cracked receiver or stock and or bent action screws.
I like the fact that one can argue with a pig... and as well they are generally more usefull and when outlived of purpose they taste great !.

[Gtek]

Ok, now everybody move back from keyboard and take a nice deep breath! Is this not a great country that we have time and thought to argue over such. One guy should just go buy a new one
and the rest of us should move on. Gtek

[Dean D.]

Enough. I believe the O.P. has gotten his question answered and this thread has turned into a urinating contest. Therefore I am locking the thread. If you want to continue your tit for tat arguments take them to PM's as you aren't resolving anything here nor making yourselves look good to the rest of our members.