Bad headspace...

[mdi]

My recently rediscovered No. 4 MkI, ain't gonna be a shooter. I tried a coin type "field" headspace gauge and the bolt closed easily on the gauge. :cry: Felt pretty bad after spending 4 days cleaning the action, stock, and barrel, reading up/researching the Mk I, and buying ammo and a headspace gauge....

Back into the closet...:violin:

[303Guy]

What bolt head number does it have? It could still be used for cast at lower pressure. The O-ring trick could be used to fire form the cases to headspace on the shoulder.

[nhrifle]

If you have a high number bolt head (3 or 4) it would be possible to build up the face of the bolt head with weld and have it milled to length to restore headspace. You would need to get an accurate measurement of what the current headspace is, with a completely clean chamber of course.

[Multigunner]

Sometimes bolt heads prove to be shorter than the number indicates.
The SMLE bolt heads were hand fitted by grinding the face down using fine sand paper glued to either a thick pane of glass or a precisely surface ground steel plate.
No.4 rifle bolt heads found to be too long to allow the bolt to close on out of spec ammo in sandy environments were sometimes ground down in the field using a whetrock. Not an approved method of course.
That along with occasional compression of the bolt heads under excessive pressure can mean that a bolt head of the same number may correct your headspace without going to the next higher size.
Only way to be sure is to mike the bolt heads.

Bolt heads got swapped out by accident and entire bolts for that matter.
Due to third world repairs, scrubbing and re numbering, and humping of serial numbers of antiques by unscrupulous dealers ,having a matching number does not always guarantee that the bolt is original to the rifle.

If the action body shows no signs of seat set back you should be able to correct head space. Replacement bolts have been available off and on.
I used a near new condition used bolt body to replace the non matching and very worn body of my Savage No.4 bolt, copped a #3 bolt head as well. Thanks to an uncommonly tight chamber fired cases now are almost indistinguishable from unfired cases.

I replaced the bolt body of my SMLE with a NOS unissued BSA manufacture bolt body, not because of headspace problems but because of badly worn bolt head securing female threads.
Springfield Sporters had the SMLE bolt bodies.
You could check with them on availability of No.4 bolt bodies.

If worse came to worse a barrel can be set back one thread and the chamber freshened, though to set back the breech of a No.4 properly you might have to use a diamond wheel to remove some metal from the internal shoulder of the receiver ring.
No.4 barrels torque on the receiver ring shoulder so some have a noticeable gap between barrel breech and internal shoulder.

Check the flat on the knox form. Sometimes rifles re barreled by importers are found to be under clocked. If so removing a few thousandths from the barrel shoulder and clocking in will reduce headspace at the same time.

If you over clock that will cause the front sight to lean to the left. This can be rectified by filing a bit off one side of the sight base lugs and shimming the other side, so long as the extractor still has clearance.
Not something they'd do when rifles were in service and they had tons of replacement barrels, but the correction would not be visible.

[waksupi]

You may also be able to fire form your brass, and shoot as-is.

[felix]

Of course, just fireforming with soft-loaded military-annealed ammo, like M80's from India. That's what I did with an Indian 308 Jungle Carbine, and that was advised by the vendor the gun was bought from. It was reputed to be his personal gun before being sold to my son at the Tulsa gun show. The gun is accurate as the M80s with 0.311 sized 165 grain military shaped LBTs using 38 grains of 50-BMG spotter powder (full case, about 4064 speed) in the fired M80 cases. These cases when sized NORMALLY won't go into a genuine 308 chamber. Shoulder too long. ... felix

[Multigunner]

If you decide to simply fire form cases to headspace on the shoulder theres no need to use factory loaded ammo to obtain cases.
You can obtain unfired cases in bulk and assemble a light to medium pressure load for fire forming.

Correcting headspace should only be necessary if you plan to use full power factory loads, or to preserve the rifles resale value.
That is of course unless headspace were so far out of spec as to cause separations or burst cases, then it would be a safety issue.

Rifles with set back so severe that it could not be rectified by normal replacement of bolt head or body would be marked ZF and sent to the chopper.

[mdi]

Hmmm. Lots of info.! My Oakie headspace gauge measures .074" and the bolt head is stamped with a number "2". Numbers on bolt handle match serial number. Wouldn't case separation be a problem with excessive headspace?

[felix]

No, unless you size the cases over the weak spot, and then you'd be in trouble. So, be careful when re-setting cases with normal dies. Reset, resize only where NEEDED. ... felix

[Multigunner]

Hmmm. Lots of info.! My Oakie headspace gauge measures .074" and the bolt head is stamped with a number "2". Numbers on bolt handle match serial number. Wouldn't case separation be a problem with excessive headspace?

Well beyond .074 is over the military maximum headspace which is .074, formerly .072, SAAMI maximum for the .303 is .071.

A new condition in spec #3 bolt head would be the best answer but these are rare.
You might find a #2 bolthead that's a few thousandths longer than the #2 head you now have. Theres some variation and the bolt head itself may have been altered or become worn.

I've never tried the O-ring method, but its sound enough, though without knowing exactly why your rifle has excessive headspace, and exactly how far out of spec it is, I can't claim to know if its safe to fire.

There are a very few gunsmiths with the tools and access to all the necessary parts to examine and repair just about any headspace problem.
Armorers used a special bolt like gauge to judge whether the action body was worth saving.

If worse came to worse you might buy a cheap but restorable bubba'ed sporter with a good action and use your rifle as a donor for parts to restore it.

[nicholst55]

Hmmm. Lots of info.! My Oakie headspace gauge measures .074" and the bolt head is stamped with a number "2". Numbers on bolt handle match serial number. Wouldn't case separation be a problem with excessive headspace?

Brian Dick at BDL Ltd did have some NIW #3 bolt heads at one time. It might be worth a phone call to see if he still does.

[bob208]

in one of the books I read on the smle, they said to sodier a spacer on the front of the bolt face to take up headspace. me I would find out how much I needed and see about getting it built up with hard chrome.

[Bret4207]

You may also be able to fire form your brass, and shoot as-is.

My suggestion too. Neck size the brass thereafter and anneal when things start looking like they want to crack. You will live happily ever after with cast.

[atr]

All the advice given above is good advise...

my personal experience with SMLE started years ago with a #5 with excessive headspace

after the first reload,,,full length resized, the case separated just above the web in the brass...so I tried neck sizing only which solved the problem of case separation. Didn't solve the headspace problem but I could still reload and reuse the brass.

ps...you could also try a Lee collett die. The die will reshape the neck only.

[303Guy]

I would want to know why there is excess headspace as a starting point. If all is good then fire-form and go. If in doubt, use lighter loads.

There is a way to fire-form new cases to a rifle with excess headspace but some would view this with disdain - lube the loaded case before firing. Not too much, just a sticky or slippery feel and not with full power loads. Moderate to light loads only.

Now I should tell you - never take advice from someone who has blown himself up and killed himself! I haven't blown myself up - yet. (I'll tell you what though, I damn near blew myself up with an un-powdered round! Not that one but the one that followed which then had a bullet lodged in the bore in front of it).

[mdi]

Well, here's the plan; I'll shoot the factory ammo and if I reload them, neck size only. May have trouble finding bullets 'cause barrel slugs at .303"/.318" and to get cast bullets I prolly would have to get a custom mold and sizing die (to .320"). Keep looking for a #3 bolt head. Starting to rethink this project...:(

But I reeeeealy like my Lee-Enfield. My Mosin is too long and I don't like the sights. My '96 Mauser is in poor shape and I don't like the sights. My SKS feels/shoots like a toy. I picked up these rifles in the '80s and did little at the time to use them, and now that I'm retired, I just figgered they would afford a bit of "classic" shooting...

[waksupi]

Well, here's the plan; I'll shoot the factory ammo and if I reload them, neck size only. May have trouble finding bullets 'cause barrel slugs at .303"/.318" and to get cast bullets I prolly would have to get a custom mold and sizing die (to .320"). Keep looking for a #3 bolt head. Starting to rethink this project...:(



If adjusting to fire form, you should partially pull the factory bullets, and seat them back to contact the lands before firing.

[Bret4207]

Well, here's the plan; I'll shoot the factory ammo and if I reload them, neck size only. May have trouble finding bullets 'cause barrel slugs at .303"/.318" and to get cast bullets I prolly would have to get a custom mold and sizing die (to .320"). Keep looking for a #3 bolt head. Starting to rethink this project...:(


You're in luck friend! There are no less than 372 gazillion skinny 8mm (.323) and 32 Special (.321) moulds out there that would be perfect for you! Sizers aren't near the problem you think either. Buskshot and some of the others here can whip you up a .320 sizer in no time, or you might be so lucky as to find you gun like your boolits from a 32 Special mould or skinny 8mm as cast!

And there you were getting all discouraged....:D

[nicholst55]

You're in luck friend! There are no less than 372 gazillion skinny 8mm (.323) and 32 Special (.321) moulds out there that would be perfect for you! Sizers aren't near the problem you think either. Buskshot and some of the others here can whip you up a .320 sizer in no time, or you might be so lucky as to find you gun like your boolits from a 32 Special mould or skinny 8mm as cast!

And there you were getting all discouraged....:D

But will it chamber a round loaded with a boolit that large?

[Bret4207]

Only way to know is to try. Measuring the ID of a case fired with a full power load will tell the max diameter he can reasonably expect to chamber.

[Multigunner]

Well, here's the plan; I'll shoot the factory ammo and if I reload them, neck size only. May have trouble finding bullets 'cause barrel slugs at .303"/.318" and to get cast bullets I prolly would have to get a custom mold and sizing die (to .320"). Keep looking for a #3 bolt head. Starting to rethink this project...:(

...
If the headspace is beyond .074 then I would not suggest attempting to reload factory cases of any sort that have been first fired with full power loads.

Here's the progression of events on first firing when headspace is beyond maximum tolerances.

The case is driven forwards by the firing pin strike till stopped by the rim.
Case walls expand to grasp the chamber walls tightly under pressure.
The case head does not expand so it does not grasp the chamber walls.
The case head is pushed back against the bolt face.
The case wall just above the web of the case head will stretch and work harden with formation of an internal annular ring of thinned brittle brass.
On subsequent firings whether neck sized only or not that thin brittle ring remains as a very weaken portion of the case, and it will sooner or later separate at that ring.

If you can't find a bolt head or bolt body to correct excessive headspace the only reasonable safe option is to limit the amount that a case can be driven forwards into the chamber.
The O-ring method seems to work, this being based on an older method where a ring of monofilament fishing line would have been put around the case head above the rim.
Tape has also been used for this purpose.

Some have formed .303 cases from .405 Winchester cases. The rims of this would usually have to be thinned unless headspace is way out of spec.
Personally I would not fire a rifle that has excessive headspace by the most extreme definition as measured by Military specifications of .074 Maximum.

My advice is take the time to find a proper bolt head and if need be a bolt body before doing any firing or handloading.
Any cases you might use at this point would be unusable later on when you do get around to correcting headspace.

PS
Lubing a cartridge case is not a good idea. More than likely the reason this rifle has excessive headspace is due to being fired with cosmoline or other grease still in the chamber. One shot would do it.
When the Indian police took SMLE rifles out of storage during the Mumbha emergency video tape of an officer firing the first shot from a SMLE he had taken from a wounded officer showed a cloud of smoke as if a black powder round had been fired. That was most likely grease in the bore. Reports after the battle told of some SMLE rifles jamming tight on the first shot leaving the officers with no means to fire back. Grease in the bore and/or chamber was the most likely culprit.

Besides the case being slippery grease around the chamber neck is incompressible which can cause the neck to bind on the bullet on firing, increasing chamber pressure.

Any headspace problem will likely get worse if not corrected properly.

[303Guy]

Any headspace problem will likely get worse if not corrected properly.I agree. The idea of lengthening the loaded cartridge to seat on the rifling leade is good but will only work if the leade is as new and even then it will raise the pressure even though the case volume has been increased. As long as that increased pressure is not over-pressure that's fine. The effects on the action will not be worse than firing a standard length factory cartridge in it with excess headspace. Excess headspace is very destructive on the action. It will peen the lug recess bearing faces. What I'm saying is headspacing on the bullet ogive is better (way better) than firing them with excess headspace. The best is holding the case head back against the bolt face somehow.


Lubing a cartridge case is not a good idea. More than likely the reason this rifle has excessive headspace is due to being fired with cosmoline or other grease still in the chamber. One shot would do it.Cosmoline in the bore and chamber is very different to lubing a cartridge (and I mean light lubing). The cosmoline would constitute a bore obstruction while lubing a loaded round in a clean chamber actually spreads the load over the length of the case, allowing the case head to settle onto the bolt face at lower pressure and allows the case to carry the maximum load it can which is not all that much. A 308 case can carry as much as 10% of the thrust load but not a 303 because of its thinner case wall but then again the pressure is lower. Anyway, lubing the case does not prevent case to chamber wall grip, it merely reduces it to controllable levels. A lubed case (not one that is flooded with oil) will still grip the chamber wall as is evident from the fact that lubed cases do not elongate. If case to chamber grip was absent the case would grow because pressure would hold the shoulder forward in the chamber while the case gets drawn rearward. All the lube does is allow the case to creep rearward, spreading the load over the length of the case instead of concentrating it at the web junction where the case would fail by virtue of it exceeding the strength of the brass at which point plastic elongation occurs, resulting in the case head suddenly moving rearward under high pressure to deliver a hammer blow to the bolt face. And that is what causes excess headspace to to increase exponentially. To the point in fact, that peening occurs which will ultimately jamb the bolt. By then the action is ruined.

I should stress light lube! Too much constitutes bore obstruction, maximum thrust onto the bolt face and possible diesel detonation of the oil getting highly compressed and spraying as a vapour into the combustion space behind the bullet as it leaves the case. One can get this effect in an air rifle - that's how little pressure is required for that. Light lube means a light roll on a lube pad - about as much as would jamb a case in a sizer die.

Besides the case being slippery grease around the chamber neck is incompressible which can cause the neck to bind on the bullet on firing, increasing chamber pressure.I had not thought of that one. Yes, that is could be more likely than the diesel effect. Two theories to consider. Perhaps both effects occur to exacerbate the pressure rise.

We've heard of wetting a test cartridge in oil for proof firing. Good heavens, no! And that with a proof cartridge?! I wonder whether that's the cause of very strong actions like the P14 having a locking lug breaking of down the line?

After all is said, I too would suggest the option of finding a replacement bolthead and fixing the problem. In the meantime - keep pressures low and don't fire those factory rounds (without an o-ring or something).

[mdi]

Well, you fellers are prolly getting tired of "Mike's Old Gun Project", but I'm retired, waiting on a couple books on my Enfield, and have time.

Yesterday I measured the bolt head. Stamped #2, the measurement is .633"-.634", which seems to be good. Another "test"; I measured the rim of a factory new round,.060", pulled the bullet and dumped the powder. I removed the primer and lightly inserted a used primer and chambered the case. I closed the bolt on the case, forcibly, but not "slammed", and measured the primer protrusion. I got .004" average out of 3 tries and a dozen measurements. So, I'm not doing something right. Bolt closes, easily on a .074" gauge, but primer test tells me headspace is only .064"??? [smilie=b:

I've been searching the web for cast bullets of around 170 grains and .320" diameter. Regardless of caliber designation I only find .323"+ or .314" available from commercial casters. I'm not gonna buy a mold and sizing die if the barrel/chamber are mismatched for shooting lead. I'm still in the research mode, and reading up on .303 cast bullet loading.

I'll either get there or blow it up with a huge over charge of Bullseye in a plugged barrel...:mrgreen:

[Multigunner]

I closed the bolt on the case, forcibly, but not "slammed", and measured the primer protrusion. I got .004" average out of 3 tries and a dozen measurements. So, I'm not doing something right.
Did you remove the extractor first?

Check the face of the bolt head.

If the bolt face is not flat and/or not level your readings won't be right.
Bolt bodies can warp causing the bolt face to be off kilter.

To get a proper headspace reading you should remove extractor and firing pin, using only stripped bolt body and bolt head.

PS
Heres factors to consider.
A strong extractor spring will cause side pressure on the bolt head as to close the action. If bolt body is a loose fit in the bolt channel at the rear walls or the bolt head threads are worn then the side pressure can cause the bolt head to shift or tilt in relation to the case head or the gauge.
Theres a fair amount of camming action when you turn the bolt home. Unless the extractor spring is interfering you should not need to use any real forwards push to close the bolt on that high primer.
If you unconsciously push forwards on the bolt handle before turning it open that would also affect results.
Softly softly catchee monkey.

[Garyshome]

Is that a Real Tight Hat?

[303Guy]

You test that result by placing a shim of that thickness between the bolt face and case head. The bolt should almost close without forcing it. An easier way would be to use a feeler gauge between the outer locking lug and body thrust face. The feeler gauge does need to be place over the thrust face with the bolt open and closed over it because of the extractor. Don't force it - that will damage the feeler gauge blade.

[Multigunner]

We've heard of wetting a test cartridge in oil for proof firing. Good heavens, no! And that with a proof cartridge?! I wonder whether that's the cause of very strong actions like the P14 having a locking lug breaking of down the line?

A practice the Indian arsenals stopped doing in the 50's due to too many actions failing proof.
The oiled proof cartridge served two purposes, to provide a worst case scenario and to complete the crush fitting of locking lug and lug recesses. Some work hardening of those surfaces added to the heat treatment as well to provide better wear resistence.
Some lug setback was expected.
The proof test cartridges used only generated 56-58 K CUP, .30-06 proof cartridges generated 70,000 CUP later upped to 75,000 CUP. Previous proof cartridges at higher pressures caused too many action failures.
Repeated hammering from wet or oily cartridges would cause metal fatigue. No telling how many times you could get away with it before the action body cracked or was deformed. if the receiver didn't crack Lug setback would accumulate till the action body failed gauging and was scrapped.
If the charger guide of an SMLE began to wiggle they scrapped the action body or DP'ed the rifle. This would indicate spreading or excessive flexing of the action body and possible cracks between charger guide rivet holes and the lug recess hidden by the charger guide. The Lee Metford and those LE action bodies without charger guide are considered stronger than the SMLE body.

When proof testing any binding of the bolt after the oiled proof round would result in be grounds for the action being scrapped with no efforts at repair.

Some are confused by the term "Oiled in the Service Manner". this was when cartridges were wiped with a flannel rag moistened with a thin oil and left to dry before being used. The cartridges would not be oily to the touch, there was no lubrication action from the residue of the thin oil and this was done only to stave off verdigris and prevent mud from clinging to the case. In very dry dusty environments no oil or grease was to be used on ammo or in the action or barrel.

[EDG]

Get new unfired PPU brass and expand the necks to about .35 to .375. Depending on what you are comfortable with. Neck back down with a .303 FL die until the bolt will close with friction due to interference at the shoulder.
Load and fire. When reloading always neck size.

[swheeler]

Get new unfired PPU brass and expand the necks to about .35 to .375. Depending on what you are comfortable with. Neck back down with a .303 FL die until the bolt will close with friction due to interference at the shoulder.
Load and fire. When reloading always neck size.

ding-ding-ding winner, winner chicken dinner. That's exactly how I would do it, create a false shoulder to set headspace on forming, then size without moving the shoulder back, old school.

[303Guy]

I wish I had thought of that! :mrgreen: Great idea :idea: - so simple.

It may be an idea to anneal first even though the cases come annealed. More annealing may be needed, I'm not sure.

I once opened a case up to 41 then sized it back down to 303 several times just to see how the brass would hold up. I think I annealed the neck/shoulder twice. Once before I started then again when it seemed to be getting hard. The neck only lost its mouth squareness and got shorter.

That's an interesting insight, thanks Multigunner.:drinks:

[neilking]

Mine has "Z"uF bulged barrel painted on the stock. Somehow made it to my house instead of the chopping block.

[neilking]

Strangely enough I shot this gun about 10 yrs ago not knowing any better. There was a piece of paper glued to the stock hiding the "Z"uF bulged barrel. Anyway it seemed to shoot fine and I was able to hit the target at 100yd so I was happy and put it back in the closet.

[Multigunner]

Mine has "Z"uF bulged barrel painted on the stock. Somehow made it to my house instead of the chopping block.

Could you post images of this rifle?
It would help to study such markings and if possible any visible sign of bulging so we could get an idea of how that happened.

No matter how diligent the British and Commonwealth armorers were many of these rifles were sold off by former client states that had little or no expertise in this type of rifle and cared only about clearing out the old warehouses. Importers with no real knowledge of such markings would then pass them on.

[neilking]

There is no visable bulge in the bore and running a tight patch through it doesn't reveal a bulge. I'll see I'd I can figure out how to post pictures.

[neilking]

Its a pretty good lookin rifle except for the green painted lettering on it

[neilking]

Look in my user profile see if you see the pic.

[neilking]

too small?

[Multigunner]

too small?

At 400% zoom I couldn't tell much about it.

Always possible that the butt was replaced from wood stripped from a scrapped rifle. I've even found a SMLE MkI butt stock on a No.4 rifle.

[neilking]

I posted better pics but couldn't link them to this thread. I'm more of a lurker....

[neilking]

http://img.tapatalk.com/d/13/11/26/5evaha6y.jpghttp://img.tapatalk.com/d/13/11/26/4y7eha6e.jpghttp://img.tapatalk.com/d/13/11/26/a7ybamaq.jpghttp://img.tapatalk.com/d/13/11/26/nu4aqeju.jpg
The main reason I posted this in this particular thread is because this guns head space is way out of spec at about .079.

[neilking]

Have you read Peter Laidler's article "Head space 101"?

[Multigunner]

Have you read Peter Laidler's article "Head space 101"?

I think you have the authors mixed up, but I've read both the HS 101 and Laidler's CHS articles long ago.

Think on this. If case head seperations are only a problem when hand loading then why would the British and every other military supply broken case removal tools? They certainly weren't using reloads.
Also if you visit enough forums you'll occasionally see posts mentioning case separations and blown primers when using factory ammunition.
Not every cartridge case is perfect, they can't inspect each and every case with any precision even if they wanted to. Cases are sampled by lots so any glaring manufacturing error will be caught.

The assumption that primer back out will always cushion the back thrust on the bolt does not consider the heavily staked mil spec primers that don't back out.
Primer cushioning effects may slow bolt thrust, but the total thrust remains the same.
Blown out primers are certainly not unheard of, if the primer backs out and a weakness in the wall of the cup is left unsupported.
Any oil left in the chamber may negate the effect of the case gripping the chamber wall, then its full bolt thrust with the case having room to accelerate and hammer the bolt, the greater the head gap the greater the hammering.

[neilking]

http://milsurps.com/content.php?r=296-Headspace-101-for-.303-s
You were correct. Different auther but an interesting article.

[Multigunner]

There's been a disturbing tendency for some gun writers to attempt to play down safety concerns as "myths".
A lot of this comes from misreading of test results run generations in the past involving military ammunition designed for use in automatic weapons.
Julian Hatcher wrote of tests on the Mil spec .30-06 ammunition of his day. In those tests a .30-06 milspec cartridge case could withstand as much as .03 head gap without bursting.
What those who read these results fail to realize is that this represents a maximum before failure safety margin, not a designed in resistence. The exact amount of margin before failure can depend on factors beyond the shooter's control.
Staked primers are staked to prevent blown cups , commercial ammo seldom has staked primers, and during WW1 soft primer cups caused quite a few problems for automatic weapons.
MG Gunners always checked the headspace of their weapons when changing out barrels, because they knew headspace does in fact matter.
Other factors to consider are the generous near maximum clearances of the Mil spec .303 chamber.
I've had new factory load Winchester .303 cases split lengthwise in several .303 rifles that had no problems with other brands of ammo. Only two or three cases split from each box, the case walls were obviously thin at the point of the splits, which were all in the same place.
The rifles used had better than average chambers, two had relatively tight chambers and all had excellent headspace of .068-.069.
The point being that one can never be sure when they will run into a factory load with a cartridge case that's thinner or less elastic than it should be.

On another board a European shooter posted images of several .303 cases with blown primers. The rifle had never had this sort of problem with other brands of primers. Each blown primer had given way on its circumference.
A primer cup with a manufacturing flaw in its wall may not split so long as that wall is fully supported by the case head, but if that primer backs out a smidgeon the flawed wall is no longer supported and the cup splits or is blown out.

What it amounts to is that when headspace exceeds recommended maximum specifications you'll be depending on a before failure safety margin every time you pull the trigger.

[neilking]

Your last statement, though a little confusing the way it's worded, is why I'm looking for
A soution. I don't consider this gun a shooter as is. Even if won't probably blow up if its shot a few times.

[neilking]

http://img.tapatalk.com/d/13/12/05/eqaru7ut.jpghttp://img.tapatalk.com/d/13/12/05/ypyza9yh.jpg
There seems to be a pretty big gap here.

[neilking]

Pay no attention to the leg. Sexy as it may be.

[Multigunner]

There seems to be a pretty big gap here.
It certainly is.
Ideally both internal shoulder and external shoulder should make contact, but the No.4 barrels were installed to torque on the external shoulder. As long as it head spaced they did not mind a visible gap. That's a bit more of a gap than normal.
The SMLE torqued on the internal shoulder. Sometimes these have a visible gap at the external shoulder, but that would not effect headspace of an SMLE.

I'm beginning to suspect that someone replaced the bulged barrel, using a take off barrel possibly from a DP rifle that had not been chamber plugged, but did a poor job of fitting it.

[neilking]

How hard is it to get the barrel off?

[Multigunner]

How hard is it to get the barrel off?

That's a job for those who have the proper equipment. It usually takes quite a bit of force to remove a No.4 barrel so a action wrench that clamps down on the receiver ring and a barrel vise with jaws that fit the contour of the barrel should be used in removing or replacing a barrel.
Torque for the No.4 barrel is quoted as 125 Lb. That's factory specs.

PS
From the size of the gap I'd say that the Bolt Body and Bolt Head may be okay. Can't guarantee it but they are most likely within specs and close to original dimensions.
The action body is also more than likely within specs without excessive setback.
Otherwise the head space would be even further out of specs.

On looking at the images once again I'm not really sure what I'm seeing.
Does the gap go all the way around the breech?
Looks like debris are obscuring the gap near the bottom..
I have seen worse, or at least more obvious gaps, and the action still headspace with a #3 bolt head.


At this point I really don't know what to tell you. I just can't say for sure without seeing the rifle rather than photos.

[neilking]

I doubt there's a qualified professional here. I'd have to send it somewhere. I'm sure there are some that say they are. I don't know how the gun field is but in mine for every good tech there's a thousand bad ones

[Multigunner]

I doubt there's a qualified professional here. I'd have to send it somewhere. I'm sure there are some that say they are. I don't know how the gun field is but in mine for every good tech there's a thousand bad ones

There are a few highly qualified professional gunsmiths on the board, but they seldom bother getting involved in these forums.
You can check in the gunsmithing tips and Barrel Works forums and ask around.

Very few U S gunsmiths work on the Lee Enfields, there are a few who do specialize in these actions.
You can check with Brian Dick ltd and get a quote on the work you may need. He has access to No.4 parts that most gunsmiths don't.
I figure he would be a bit leery of the ZF marking though, he might not want to work on a rifle that's been officially condemned.

A good man knows his limitations. I always had re-barreling done by a friend who had all the tools and plenty of experience building long range target rifles and Law Enforcement entry weapons, Lee Enfields were his hobby and he had some fine examples. If he were still around I'd have you mail the rifle to him.

[neilking]

I'm gonna put it on the back burner till I get my lathe set up. Then if I can get the barrel off I'll true up the breach, and cut the shoulder a little at a time till it indexes property.

[neilking]

By the way. The gap is right around .020 all the way around. Do you know the tpi on the barrel. I'll need to know the distance of one turn.

[neilking]

I have not been able to find a #3 bolt head. Maybe I could just get another one and build up the face till I get the head space I want.

[neilking]

And leave the barrel alone

[mdi]

Anyway, back to the pre-hijack thread; I shot some factory Remington 180 Core-Loct through my Mk I*. I fired one round, it extracted easily, and measured the case length. Within .001" of an unfired case, no primer protrusion. The case diameter just in front of the extractor groove was within .0005" of an unfired case. No bulges anywhere in the case. So, I shot 18 more, not seeing/experiencing anything different/odd about the gun. I measured all 19 cases and found no primer protrusion, no variances in case length or diameter. Fair to poor accuracy (a new to me gun, not the best conditions, etc.), mebbe 3"-4" at 50 yards. I'll either find some bullets a bit larger (.320" or so) and swage them to .318, or get some cast and size them to .320" or so...

Back to you neiking...

[303Guy]

mdi, perhaps shoot the .320" boolits unsized?

neilking, I'd suggest not touching the barrel itself but rather fitting a shim between the breach face and inner receiver shoulder. Give the shim a step to hold it against the breach face. It would necessarily have a piece cut out to accommodate the extractor. It need not be a tight fit so aligning the gap could be done after tightening the barrel. Mind you, if the shim was flat it could be held against the breach face by squeezing some epoxy putty between the shim and the inner shoulder. Maybe a half shim could be fitted without taking off the barrel if you can clean out the gap well enough.

[Multigunner]

Anyway, back to the pre-hijack thread; I shot some factory Remington 180 Core-Loct through my Mk I*. I fired one round, it extracted easily, and measured the case length. Within .001" of an unfired case, no primer protrusion. The case diameter just in front of the extractor groove was within .0005" of an unfired case. No bulges anywhere in the case. So, I shot 18 more, not seeing/experiencing anything different/odd about the gun. I measured all 19 cases and found no primer protrusion, no variances in case length or diameter. Fair to poor accuracy (a new to me gun, not the best conditions, etc.), mebbe 3"-4" at 50 yards. I'll either find some bullets a bit larger (.320" or so) and swage them to .318, or get some cast and size them to .320" or so...

Back to you neiking...

I've seldom gotten decent accuracy from either Winchester or Remington factory loads. The SMLE I have now gets great accuracy with everything put through it, but that's because it has a unusual true .311 bore. That would put this barrel below the stated minimum bore size, but I've heard of No.4 rifles with bores as small as .309. They had very wide tolerances on bore diameters at the best of times, and during war time they seem to have just made sure you could see daylight at the other end before passing it.

The powders used by Remington and those used by Winchester don't seem to bump up the bullets much at all, or the bullets themselves resist bumping up.

The Remington case has worked fine in all my Enfields. I buy them by the 100's. Haven't bought any for years because after correcting headspace I haven't lost a single case to cracking. With good headspace and a reasonable chamber the Remington case will last for 30+ reloads.

If you use significantly oversized boolits make sure the chamber neck allows enough clearance for a clean release of the boolit.

I suggest that anyone who has a hard used milsurp rifle should aggressively clean the chamber neck.
You would be amazed at the amount of baked on fouling that can accumulate in the neck if the rifle was not properly cleaned while in service.

I had flattened primers with my No.4 before I made a scraper out of brass tubing and scraped away a thick layer of stuff that looked like the material of the old 78 rpm record disk. BTW they used salvaged nitrocellulose from condemned smokeless propellants to make those records, and also for water proof wood glues and furniture finishes.

[Multigunner]

By the way. The gap is right around .020 all the way around. Do you know the tpi on the barrel. I'll need to know the distance of one turn.

Lee Enfield barrel threads are 14 TPI.
I took awhile getting back to you because I wanted to find this link for you.
This was posted by another board member some time back.
https://docs.google.com/viewer?pid=explorer&srcid=0B9CVQ-oEZUA1LWF5OXpWMGZWSTA&docid=bb8d1c605f07201fc433471f5571d805%7C6433c24ea 306819016f4f8c248e93c07&chan=EAAAACne6jv/8/%2BOotepl5AjZEciRBAXReo/1/aClWvsTHtX&a=v&rel=zip;z4;Action+Threads.pdf

I've found these scans on other boards long ago, don't know the origin.
Very handy information.

[flounderman]

It is my understanding the british used replacement bolt heads that were made to compensate for headspace deficiencies. If the rifle developed headspace they replaced the bolt head with a thicker one.

[Multigunner]

It is my understanding the british used replacement bolt heads that were made to compensate for headspace deficiencies. If the rifle developed headspace they replaced the bolt head with a thicker one.
Unfortunately #3 boltheads are rare as hens teeth. I have one but I'm not about to part with it.

[mdi]

Not an expert, but I read the interchangeable, different thickness boltheads were designed for ease of fixing the headspace at time of manufacturer. I have nothing to back that up, 'cause I only have 5, so-so books on the Lee-Enfileld and most of the info is only about the very basics, series, serial numbers, and differences between series and "Marks"...

[neilking]

Thanks Multi.

[303Guy]

The thread form is not shown. Is it 55° or 60° ? Actually, I have Howe's double volume 'The Modern Gunsmith'. I should find it and have a look.


different thickness boltheads were designed for ease of fixing the headspace at time of manufacturerThat is my understanding too. The numbered boltheads were a No4 innovation but the different length/thickness was the way it was done. The number one bolthead also came in an oversize blanc which could then be custom fitted to a particular rifle. Peter Laidler did an write-up describing the process of fitting boltheads fo the Lee Enfield. Do a Google search for articles by Peter Laidler.

[Multigunner]

The thread form is not shown. Is it 55° or 60° ? Actually, I have Howe's double volume 'The Modern Gunsmith'. I should find it and have a look.

That is my understanding too. The numbered boltheads were a No4 innovation but the different length/thickness was the way it was done. The number one bolthead also came in an oversize blanc which could then be custom fitted to a particular rifle. Peter Laidlaw did an write-up describing the process of fitting boltheads fo the Lee Enfield. Do a Google search for articles by Peter Laidlaw.

Do you mean Peter Laidler?
The SMLE/No.1 had the longest bolt heads marked with a tiny s. I have one of these on my SMLE bolt.

When rifles became worn the armorers were instructed to try salvaged used boltheads first before fitting an s marked bolt head.
They seldom discarded a used bolt head because it might work fine with another bolt body.
When an over long bolt head was used they hand ground it to fit using fine sand paper glued to a flat surface.

The numbered bolt heads of the No.4 rifle made adjusting headspace at the factory easier and also made it easier to rectify headspace of a worn rifle later on.

I suspect some of the numbered bolt heads were ground to fit as well since many of these are shorter than the listed dimensions of that number. Compression of the metal from repeated firings might also be a factor.

[303Guy]

Thanks for that Multigunner and yes, I meant Peter Laidler (correction made).

[neilking]

http://img.tapatalk.com/d/14/03/01/gumyryqu.jpghttp://img.tapatalk.com/d/14/03/01/ejezy5uj.jpghttp://img.tapatalk.com/d/14/03/01/javy8emu.jpghttp://img.tapatalk.com/d/14/03/01/upabuhe9.jpg
Update:
Got my lathe set up and made a head space guage and found a use for old discett labels. Found that the bolt closed snug on .070 but would not close on .074! I guess my method of adding a spacer on a cartridge and measuring was inaccurate.

[neilking]

http://img.tapatalk.com/d/14/03/01/dy9y6ady.jpg
May be hard to tell. This is the bolt closed on .070. The above pic is od the bolt not closed on .074

[Multigunner]

A frien had a scale by which you could get a good idea of the exact headspace by measuring the gap left when the bolt did not close on the .074 gauge. Don't know how accurate that would be.
Looks like you have good headspace so far as shooting goes, only close examination of the fired cases will tell how good it will be for reloading.

I've seen cases from a rifle with maximum headspace that did not form and anular ring. The chamber was tighter than average, highly polished and very slick, which would reduce the amount of case wall stretching. Cases lasted at least as long as cases from rifles with better headspace but rough oversized chambers.

With a tight chamber and headspace of less than .068 case life is normally very good without resorting to O-rings or other tricks. A lot depends on rim thickness.