L39 & L42 Barrels - An open offer to forum members

After checking to make sure this is OK, I have an offer to make to the board.

By profession I'm a draughtsman. I've been trying to build up an L42 clone myself for quite a while, and I have a vested interest in the availability of high quality barrel drawings for the L42 that any one of us can send off to our barrel maker of choice, the more so for those of us who live here in the States as importing these barrels has been illegal since 2005. So here’s my offer:

I have a barrel drawing started based on the few hard numbers I have been able to secure from members of this board and other L42 owners. I will provide blank versions of this drawing to anyone who would be willing to visit Fultons and manually copy the (probably copious) notes on their original barrel drawing and return it to me. After receiving the marked up drawing I will transcribe the notes into AutoCAD and post the completed drawing on the forum for the use of the membership in both PDF and DWG formats.

Grant580 has graciously agreed to vouch for my drafting ability and anyone with questions in that vein should contact him.

Cheers!

Have you not tried asked the National Firearms Centre in Leeds, UK, for a copy of the Drawing? The Library section should be able to help!

I wasn't aware of them, actually (the down side to doing this from the wrong side of the pond). Thanks for the lead!

You could ask, but don't hold your breath. The drawings remain the property of BAe and the NFC at Leeds are now a large money making concern following several years of being a money losing concern. I don't want to put you off but just make sure you have deep pockets.

Bearing in mind that I'm not a Draughtsman but just a mechanical engineer who's had to read many, then looking at this project from the cheap and the simple engineering side, the base for this is a simple tube, slightly tapered from one end to the other and should be simple to put into drawn form. The knocks form/breech end/extractor way is identical to the No4 and likewise, should be a simple back engineering/drawing job to calculate and index against the breeching up thread. The rifling is a known - depending upon which form you specify.

The only real info required is the depth of the shoulder in the chamber from which the CHS is measured in relation to the breech end in relation to the breeching up surface. That should be easy to calculate mathematically knowing a) where the breeching up surface is - at the end of the knocks form and b) that the max CHS measurement is 1.635 plus .001" (that way you get a 0 bolthead.....). The end of the CHS gauge to the breeching up surface deduct the 1.635 and that's the depth of the shoulder!

Yep............... I think you could do without the original drawings because you aren't going to replicate the hammer forged finish in any case.

Those are just my thoughts while idling my time stuck in a traffic jam in Devizes

The drawings are BAe property??? Well, that explains a lot. I never got a clear answer, but was led to believe that it was Nottingham SAF who held the copyrights so, by extension, H&K.

Really, what I'm looking to find on the original drawings are the machining tolerances, as well as some of the minor details like the muzzle crowning. I've got measured dimensions on both ends of the taper, as well as at the diameter of the parallel section the frontsight block is fitted on, so let me ask, your view is that should be enough?

SO to clarify - the long term goal here is to have a manufacturer of these barrels in the USA? that would be bloody great. I'm constantly amazed by what clever folks we have around here. I'd be in for a spare for when my barrel gives up the ghost in about another 5000 rounds

---------- Post added at 03:32 PM ---------- Previous post was at 03:25 PM ----------

To clarify - I would buy one NOW to keep for when my barrel gives up, and I'd probably buy another for a project for fun.

Hi newcastle,

Yep, since none of us here Stateside can import the barrels, that's the plan.

Cheers!

I know we've talked about this Longshaor, but for the interest of others, what would make such a barrel illegal to import to the USA?

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Originally Posted by Surpmil

I know we've talked about this Longshaor, but for the interest of others, what would make such a barrel illegal to import to the USA?

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It maybe because now that 7.62 is classified as a 'military calibre' and the UN have 'banned' sales / exports of military calibres except to Government Agencies.

Here is a copy of a post I made a couple of years ago :

"Target Shooter Magazine – December 2009

Target Shooter December

5.56 and 7.62mm ‘Outlawed’
A perennial question is about the difference if any between 7.62X51mm and .308 Winchester (or 5.45X45mm and .223 Remington). And while there are small differences primarily in the chamber and barrel throat forms, they are so nearly indistinguishable that the UK national police firearms licensing computer uses both terminologies together either side of an oblique to avoid problems if an FAC variation is for one, but the firearm is marked and proof-tested for the other. This applies particularly to British and Commonwealth TR (‘Target Rifle’) rifles that were classed as 7.62mm until recently, although current builds or recently rebarrelled examples now bear the .308 Winchester descriptions.

None of this would be of any great import if it weren’t for the United Nations having started a crusade against international movements of military small arms and ammunition except on a government-to-government basis. The problem is that 5.56 and 7.62mm are classified as ‘military’ period, no matter that it’s a single-shot target rifle and your pride and joy. This is a particular problem for anybody traveling across international boundaries as an early result has been airlines, through their international regulator IATA, accepting these rules and refusing to carry anything so marked or documented, even if on a dual basis as in ‘7.62mm / .308 Winchester’. The next worry is that as countries sign up to the various UN accords on this issue, we’ll suddenly discover that somebody has done this for the UK and unwittingly made ownership of every .308 Win rifle in the country illegal as our FACs invariable use the dual title in listing the weapons held. In any event ICFRA, the international target shooting body which regulates full bore rifle including our ‘Target Rifle’ and F-Class, has deleted all reference to the metric versions of the two cartridges in its rules and documentation, and I imagine that applies to our NRA too.

Firearms law researcher and writer Colin Greenwood has been investigating this UN process and his findings must be deeply unsettling for all sporting and recreational firearms users. The sub-committees tasked with producing reports and recommendations that are often accepted by the UN with little or no debate are secretive, refusing to disclose their membership or the remits they are working to. They will not divulge the basis of ‘facts’ contained in their reports, how research was carried out and where, who
was interviewed and so on. One fact that is clear are that they will NOT make any distinction between civilian sporting arms, (even shotguns), and military weapons, and that they believe that arms ownership is a bad thing per se. Greenwood is convinced that this is a movement towards international civilian arms control via the back door under the cloak of keeping AKs and RPGs out of the hands of African child soldiers or guerrillas.

Things may get ‘worse’ too in that the proposed conventions seek to ban the manufacture of arms and ammunition of ANY type and ANY calibre, except by government licensed concerns which must be closely regulated. Quite right too you might think, but remember that your gunsmith is an ‘arms constructor’, and you are an ‘ammunition' manufacturer’ if you hand load. Until now, the US government has been a bastion against this sort of undemocratic backdoor control by routinely telling the UN to naff off! Not so now under Barak Obama, the State Department allegedly signaling a change of policy here, its first move being to announce that export licenses will not be issued for any barrel chambered for 5.56 or 7.62 NATO destined for a commercial end-user".

Brian Dick may care to comment - he did post some time ago about the 'new' restrictions and paperwork involved in exporting an L42 even tho' it was C&R.

Alan,

Thanks for posting this and clarifying the issues involved with shipping such items internationally.

As far as how much the UN regs will affect the US internally, frankly, the UN's repuation is little better than that of a 'scarlet woman', and is close to universally dispised here inthe States. Any politician seen as being their stooge, except for certain fringe left-wing areas of the country, can pretty much kiss their political career good-bye.

That may be true but sadly the man at the top is very much a stooge of the UN and thus we wait for korean garands and 7.62 barrels in vain.

Regarding the remaining tolerances and material...... Maybe Ensci can give us the exact material spec that I couldn't get when I was writing about it. But it was certainly a good quality material and cut like a dream. As for the breech thread spec, then without any doubt, this will be a bog standard BSI (British Standard) 1" 12 (or is it 14?) TPI whitworth 55 degree form to the same BSI tolerances. I'll gauge a few barrels up to get a ball park chamber depth with a 1.635 CHS gauge.

The machinist/barrel maker could experiment a bit by 7.62mm chambering a few scrap No4 barrels. (He only needs to chamber ream as far as the 7.62mm neck and there's sufficient meat in a .303" chamber to form a 7.62mm neck sufficient to make a few depth calculations.......).

The muzzle crown is what it is. The foresight block band is a different matter. The early ones that were not accepted for service use had the bog standard No4 foresight block band but the service standard had a larger diameter, But this varied wildly ( I mean wildly in engineering terms.......) The bored out L42 block band wasn't available as a spare part because of this. If you needed to replace it, the rifle was sentenced to a Field Workshop and an existing No4 block band was machined to suit and re-sweated on

To be honest, with a barrel blank of sufficient length and diameter and a decent set of drawings, anyone half decent turner with a decent lathe could turn one up - or down - in a few hours

Much of Europe and also (I believe) Australia, have lived with anti military calibre regulations for many years. One of the cheaper solutions is to modify the chambering a small amount and call it something else (re-proofing of course), using same bullets and almost identical performance i.e; 7.7x54 instead of .303". This may not satisfy the purist collector but these dumb regulations could breath some fresh life into a variety of old wildcats.

The BATF&E banned all imports of surplus military barrels to the USA in July 2005. It is being litigated but with the current political climate, chances are slim to none that things will change. The interesting part is that identical barrels manufactured overseas for commercial sale can be imported.

---------- Post added at 07:49 PM ---------- Previous post was at 07:40 PM ----------

I forgot to mention that Alan de Enfield is exactly right about the State Department denying approval of export licenses for firearms and barrels in caliber 5.56, 7.62 and .50 M2 destined for end users other than the police or military.

Standard No4 barrel data:

Thread is 1.001" x 14TPI Whitworth (55deg.) form. (NOTE SMLE and Martini thread is 49deg. 40min included angle, NOT 55 and DEFINITELY NOT 60deg.)
Crests flattened to min 0.996" dia.
Pitch dia. 0.9553"; 0.9523" min.
Max allowable eccentricity of thread to bore: 0.004" (radial) or, 0.008" "clock" (diameter) reading.

VERY IMPORTANT:
Headspace on the L-42 is different!!

As per page 111 of the excellent book on the No4 T and variants, by some chap called Laidler (and Skennerton):

GO gauge is 1.628"
NO GO gauge is 1.635"

These are different from the sort of gauges that you whack into an L1A1 or M-14, let alone .308" Win gauges.

From p.110 of said tome: The material is EN 19AT steel.

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Originally Posted by Peter Laidler

BSI (British Standard) 1" 12 (or is it 14?)

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Must be a sign of the Alzheimer's setting in ? 14 TPI ,

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Originally Posted by Peter Laidler

To be honest, with a barrel blank of sufficient length and diameter and a decent set of drawings, anyone half decent turner with a decent lathe could turn one up - or down - in a few hours

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The important thing is a Taper turning attachment, one of these and your in business, but to be honest, most barrel blank suppliers will contour any blank for little cost and I know Lothar Walther charge approx $65, 41 pounds (pound sign not working on laptop) for the ammount of time setting everthing up, and your own time on the machine etc, more cost effective to let them do the contour including the Tenion, the finish is excellent, so you will have a blank with correct contour and a machined tenion ready for the thread and chamber.

Most expensive part is the Chamber, If you buy your own reamer easy enough to do, Think in the USA you can rent them? that leaves the thread, no need to worry about the thread start, just machine thread and add knox form on completion of the final CHS.

One cheaper way of doing it, is to look out for any old target rifles based on the No4 action, plenty still about with hammer forged barrels, still may need to make a spacer etc for correct CHS and still need a reamer.

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Originally Posted by Brian Dick

The BATF&E banned all imports of surplus military barrels to the USA in July 2005. It is being litigated but with the current political climate, chances are slim to none that things will change. The interesting part is that identical barrels manufactured overseas for commercial sale can be imported.

---------- Post added at 07:49 PM ---------- Previous post was at 07:40 PM ----------

I forgot to mention that Alan de Enfield is exactly right about the State Department denying approval of export licenses for firearms and barrels in caliber 5.56, 7.62 and .50 M2 destined for end users other than the police or military.

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That's interesting Brian. So that L42 you were posting about exporting earlier this year(?) and how it remained in some sense the liability of the previous owner/exporter even after the buyer in Canada (?) got it; that would no longer be exportable now?

There were plenty of hammer-forged Enfield barrels sold direct to the civilian market, why would these be banned? I have one here that has no markings, not even UK proofs, except "CR1470 D69* SRM2" (*Enfield "D") Why should a barrel like this be blocked from import to the US?

Sorry about the duff gen re the TPI Big Duke and others. It's caused by thinking on your feet and remembering your 6th form science lessons where Mr Percy always told us that in order to save brain space, to never deliberately remember anything you could easily look up in reference book. Good job we have Machinerys handbooks!

On a similar subject to the thread, my pal and I machined a 7.62mm L4 Bren barrel down to fit his No5 rifle. While we didn't have to ream a chamber, we still faced the CHS problem so we took the breeching up shoulder against the breech face against the breech end and calculated everything mathematically - and it worked. Like Big Duke suggested, we cut the extractor slot approximately but had to finally hand correct it by a tad to get it correct. The breeching up flat was also out of true but what the hell! It still breeched up, he's still got it and is still shooting it! After it had been through the workshop system it looked like new.

Regarding the UN and their embargo's...... In Bosnia my friend Maj Alistair XXXX thought that UN stood for Useless fxxxxxg Numpties

Hi Surpmil,

You're exactly correct. Even the L39A1 is banned from export. The State Dept. caliber policy was put in effect in November 2009 if I remember correctly. I managed a couple to a collector in Canada a year ago and was lucky to get them approved. The Chief of the DDTC made the exception but then told me not to ask again. It's only because the buyer and myself are well known to him that he allowed them to go.

There are supporting documents required. I must have an invoice from the manufacturer to prove that it's new and for commercial use/resale. Many think that the examiners and Chiefs are stupid and ignorant or both. It's simply not the case. I have great respect for the Chief of DDTC, US Dept. of State and many of the examiners. I also have respect for many of the examiners at BATFE Imports Branch. They are doing a job, treat me with respect and I've actually forged a good working relationship with them over many years. Most are retired or former military and some are enthusiasts themselves. I've helped them out a bit in the past. I've been involved in the hopeful retransfer of the M1 Rifles and Carbines from Korea, (it's not over yet), and they help me as much as they can in return.

Brian

---------- Post added at 11:11 AM ---------- Previous post was at 11:07 AM ----------

Hey Peter, the sun's out! I'll be in the workshop shortly!!

Quote:

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Originally Posted by bigduke6

The important thing is a Taper turning attachment, one of these and your in business, but to be honest, most barrel blank suppliers will contour any blank for little cost and I know Lothar Walther charge approx $65, 41 pounds (pound sign not working on laptop) for the ammount of time setting everthing up, and your own time on the machine etc, more cost effective to let them do the contour including the Tenion, the finish is excellent, so you will have a blank with correct contour and a machined tenion ready for the thread and chamber.

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Talked "ftf" with a Lothar Walther man today (purely by chance). He indicated that doing a barrel complete with the hammer forged "scale" finish would likely be very cost prohibitive for a short run, as the set up is far more involved than doing a net near shape with a finish turn. Oh, well...

JM, could the hammer forged finish be simply replicated as a 'finish' as opposed to a manufacturing process. I just can't think of any process or even a requirement for such a finish offhand - unless you can. Just a thought while idling away on a Saturday afternoon

Why not just do the tapered stepped variant? It's every bit as good and a bit harder to find on original rifles.

I agree entirely Brian. But if it's originality that some want and all that......

Quote:

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Originally Posted by jmoore

Talked "ftf" with a Lothar Walther man today (purely by chance). He indicated that doing a barrel complete with the hammer forged "scale" finish would likely be very cost prohibitive for a short run, as the set up is far more involved than doing a net near shape with a finish turn. Oh, well...

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Jmoore, think we have our wires crossed, I was meaning a contour with the standard ground finish, (no snake skin)

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Originally Posted by Peter Laidler

Sorry about the duff gen re the TPI Big Duke and others.

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Only joking about the Alzheimer's, I cant remember much these days unless I,ve an interest in it, and would say the worst part of giving up smoking was not having a ciggie packet to jott down notes, phone numbers, addresse,s, measurements etc.
Nine years later just seem to have torn and scrap bits of paper in the pockets when I,m at work.

Quote:

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Originally Posted by bigduke6

Jmoore, think we have our wires crossed, I was meaning a contour with the standard ground finish, (no snake skin)

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No, not really. I was just hoping (dreaming) he'd say: "Sure, no problemo! How many do you want? Discount price for ten." ;)

Quote:

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Originally Posted by bouletbill

Much of Europe and also (I believe) Australia, have lived with anti military calibre regulations for many years.

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That rule was dead and buried here in Australia years ago.

Quote:

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Originally Posted by Brian Dick

Hi Surpmil,

You're exactly correct. Even the L39A1 is banned from export. The State Dept. caliber policy was put in effect in November 2009 if I remember correctly. I managed a couple to a collector in Canada a year ago and was lucky to get them approved. The Chief of the DDTC made the exception but then told me not to ask again. It's only because the buyer and myself are well known to him that he allowed them to go.

There are supporting documents required. I must have an invoice from the manufacturer to prove that it's new and for commercial use/resale. Many think that the examiners and Chiefs are stupid and ignorant or both. It's simply not the case. I have great respect for the Chief of DDTC, US Dept. of State and many of the examiners. I also have respect for many of the examiners at BATFE Imports Branch. They are doing a job, treat me with respect and I've actually forged a good working relationship with them over many years. Most are retired or former military and some are enthusiasts themselves. I've helped them out a bit in the past. I've been involved in the hopeful retransfer of the M1 Rifles and Carbines from Korea, (it's not over yet), and they help me as much as they can in return.

Brian

---------- Post added at 11:11 AM ---------- Previous post was at 11:07 AM ----------

Hey Peter, the sun's out! I'll be in the workshop shortly!!

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Thanks Brian, that's most helpful.

So only new barrels are allowed to be imported?

Or if used barrels are allowed, what are the criteria for admission?

The drawings for this barrel, CR 1470, should be available from the Royal Armouries Library at Leeds without too much difficulty or expense. As they pre-date the privatisation of the Royal Ordnance Factories in 1985 they were Government owned and, being over 30 years old, I would imagine they can be made available to the public without copyright problems.
The steel spec was BS970 EN19 AT.

Surpmil, You're correct. New, commercial production barrels are importable. Used, commercial barrels are also importable. All require the previously mentioned invoices and/or documentation. New or used military surplus barrels are not importable under any circumstances except for police or military end users.

Brian

It would not be impossible to get the hammered finish, there are some HF barrel makers that could be contracted.

The hard part is getting the correct timing of the threads without a print or a master gage, ask anyone who has made M1 Garand or M14 barrels
(I have made them and what a pain) This is not undoable with the right intel. I am sure someone out there has the prints we are looking for it just a matter of kicking over a bunch of rocks.
15 years ago the prints for M1' M14 and M1911's were impossible to find, then POOF you can get them all over the place.

I wonder why there have never been aftermarket barrels for Enfields, they make barrels that are much more complicated, even AK barrels.

Peter, How are the prints not the Queens copyright?

I wouldn't bother trying to replicate the hammer forged look, if you make it identical to the service barrel, you will not be able to pass it off as a commercial barrel to import.
At least this way you can point to the obvious difference.

M4C, the indexed breeeching up thread isn't a problem in the L42/39 case because you'd just cut the breeching up flat and extractor way to the position of the thread. There's no foresight block lugs or bayonet lugs to think about.

M4Carbine,

To answer your questions:

1. I know where at least one copy of the drawing in question is (in fact they have copies of ALL the 7.62mm Enfield drawings, L8, L39, & L42), I'm just on the wrong side of the Atlantic Ocean to be able to nip over for a look, hence the original terms of my offer. If I could get my tail over to Bisley, I wouldn't have bothered everyone with the request.
2. As it has been explained to me by several people, while here in the States military equipment developed for military use by taxpayer funds is public domain as we, the taxpayers, have all payed into its development, in the UK such things are considered Crown Copyright - which doesn't mean 'Crown' as in the Sovereign directly, but rather Her government. When HM Government privatized Royal Ordinance in the mid-1980s, a large proportion of what had been Crown Copyrighted material which was still in service with HM Forces was transferred as part of that act and became BAe copyright. Beyond that is a little fuzzy to me, I was informed over a year ago by Stuart Ivinson (Assistant Librarian at the Royal Armouries Museum, Leeds) that Nottingham Small Arms Factory, who was the 'direct' copyright holder, had been sold by BAe to Heckler & Koch, though I have had absolutely no luck in eliciting any sort of response from them, so I'm starting to wonder if Peter is right and the info in question is still BAe property.

If anyone who has more recent/direct information about who the copyright holder is, please feel free to chime in and set the record straight!

Quote:

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Originally Posted by Brian Dick

Surpmil, You're correct. New, commercial production barrels are importable. Used, commercial barrels are also importable. All require the previously mentioned invoices and/or documentation. New or used military surplus barrels are not importable under any circumstances except for police or military end users.

Brian

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Thanks again Brian. And in cases such as the Enfield hammer-forged barrels which were identical for both civilian and military markets what would be the deciding factor?

Although that may be academic since no paperwork can be obtained from a defunct manufacturer of course.

Is this requirement for paperwork for each item not a change of policy from the previous practice (at least in some areas) of setting a policy in regard to all examples of particular types of equipment once their origin and eligibility as a type is determined?

To add another snippit of information here - Armalon (London, UK) have the complete Parker Hale barrel hammer forging machinery up and running again. If you can get the drawing, you could have as many new commercial 'real' L42 barrels made as you wanted....

http://www.armalon.com/public/static/page/4

There's the rub Nick.............. If you can get the drawings - and you can't! The drawings should be simplicity itself to replicate. You are just back engineering a tube. The biggest hurdle you will face in the UK is finding someone with phosphating facilities

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Originally Posted by Peter Laidler

The biggest hurdle you will face in the UK is finding someone with phosphating facilities

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The link Nick s provides, says something regarding " blackening" so I guess they have the facilities to do phosphating or they have another company to do it.

Good luck to Armalon as they would be the only barrel maker in England, but would say it all depends on the price and quality, but in the meantime if anyone does require a barrel blank then let me know as I will ordering soon from Lothar Walther.

I have an Armalon hammered barrel on an AR15 - quality is very good, and life expectancy should be better than the Border it replaced... It's chemical blacked, rather than phosphated, but having said that I know of at least 2 companies that do phosphating...

Surpmil, Factory invoices have always been required for new manufactured firearms and/or components. There is other documentation required for surplus military or commercial firearms stating where the items were stored for a particular number of years. Barrels manufactured by the RSAF are going to be deemed as military surplus regardless of whether they were marketed commercially or not. I've been down the school of hard knocks on this, (there is no other school that I know of!), and without the required paperwork, it isn't worth the effort of submitting the import license application. I remember when Springfield Sporters had new five groove BSA No.4 barrels for $30 each by the case. I sure wish I had the money to sock in a couple of cases in those days. Brian

Phosphating is widely used in teh automotive trade as a surface treatment for things like crankshafts and camshafts. As in small arms worl, the idea is to provide a stable crystaline skin on the base metal. Both surfaced basically provide a semi-permeable skin into which oil can penetrate and thus protect the steel.

The actual phosphating is a fairly simple procedure; whack the item in the hot brew and wait for the right colour.... BUT!!!

Like blueing, the preparation is VERY important.

It is also different.

A "proper" phosphating job requires that the steel surface be "activated". The usual procedure is to grit or glass-bead blast the item IMMEDIATELY before immersion in the phosphoric acid bath. What this does is to remove any other oxides that may have started forming, and by distorting the surface, (on a very tiny scale), said surface is still "lively" at a structural level when it hits the bath.

The colour of the finished product can be varied by the choice of metallic additives in the bath: Manganese for black, Zinc for grey.

Temperature can sometimes have an effect: If the item is de-greased and then pre-rinsed in very hot de-mineralised water it will not cause a "blip" in the bath temperature when immersed. Some more exotic alloy steels respond better if the whole bath starts at a lower temperature than normal and is then brought up over a minute or so. On a side note, this trick also works with attempts to blue interesting alloy steels. It avoids the purple and maroon tints occasionally seen. Supplementary side note: VERY lightly bead-blasting hardened exotic alloy steels before blueing, produces a deep, satin-black finish; very nice on small-arms components.

After the item has achieved the desired colour, it is thoroughly rinsed with very hot water and drenched in de-watering fluid. It should then be coated with a medium grade oil whilst warm. If you just let the thing dry off, it will start to rust while you watch.

Setting up for and maintaing a phosphating rig is probably simpler than establishing a blueing plant, but neither are for the casual user. You can do it on a small scale but unless you have lots of stuff that needs doing or lots of friends with interesting projects, it could get expensive.

Great analogy there Bruce. I've been phosphating firearms and accessories for 30 years and I can't add a thing to your words. Brian

Yes, excellent summary. I have been using phosphating for 20 years for the No32 brackets (before suncoriting them afterwards). I was given a recipe by an old friend who worked for a leading UK aerospace/defence contractor & it is simply 33.3% concentrated phosphoric acid; 33.3% methylated spirits; & 33.3% water. As Bruce said, you can vary mixes to give particular colours, but I've never bothered - the finish I get is functional, & it shortly gets painted over anyway!

ATB

PS I use the same method on scope tubes & No4 receivers, to get that 'milspec' finish.

for us in Australia/New Zealand (great win today in the test cricket fellas) check the following link, it is TSE ( barrel making mob here in Oz) data sheet for custom profiles. if anyone with the required info could fill that out send it back to me or TSA with the lengths of the barrel, then I am pretty sure they can do a barrel.
Dunno if this helps but could be a local solution for those interested.

cheers
Ned

Custom Barrel Profile