First some clarification needed.
The following quoted posting attributed to Peter Laidler has been quoted numerous times recently to supposedly prove that Cordite erosion can not produce an unsafe bore.
The above is I suppose is a reaction to the following.Right, here goes, now that we've got a bit more meat on the bone. I have to tell you that I'm not a chemist and my physics is limited to Uni level mechanical engineering. But I MUST stress here, that the break-up of No4 barrels in Cadet service was played up out of all proportion. EVERY single weapon in the British Army is examined AT LEAST once every year by the unit Armourers and if the unit doesn't have a unit Armourer, such at Cadet Forces and outlying TA units etc etc, then a what we call P.R.E. team travel out and examine them. They have a Landrover or a van and all the gauges. The PRE armourer is usually a time served ex apprentice and retired so he is on top of his game.
He ascertains the mechanical status of the weapons and if it's unserviceable, then it's called in and scrapped. It's as simple as that! There is NO SUCH THING as a dangerous weapon being left '....just because it's for the Territorials or Cadets' It simply CANNOT happen......., never, not even in 20 years (But someone out there will know better, I can feel the flak coming in already. Helmets on lads!) If it is left, awaiting call in to workshop or Ordnance, it will be clearly labelled with a special form called an AFG 1045, a workshop call-in form ..... or something like that! But obviously, the unserviceable DP rifles will remain.............
Of the two rifles that hit the headlines, the spectacular one, when a Cadet lost a couple of fingers. Let me tell you about that one. At the time, the RAF still retained their own Ordnance system for Cadets and this rifle was a DP rifle. The RAF method of DP'ing was to bore a xxxxing big 3/8" hole down, through the top handguard, through the barrel and through the fore-end and had the letters DP stamped in equally xxxxing big letters all over the rifle. However, they weren't marked with white bands like the Army versions. Anyway a Cadet, under supervision (?) on a range, fired this rifle and naturally, it didn't go bang because the bolt was welded up and the striker was short. So the supervisor, put another bolt in and this time it DID go bang ....., in a big way which took a couple of fingers off.
It was said that he looked at the fore-end when the rifle was in the rack but there was no hole visible. They didn't find sufficient wood after it blew to state with any certainty that it DID have a xxxxing big hole. Mind you, it certainly DID have a xxxxing big hole after the event!
It was nothing to do with the rifle at all and the Board of Enquiry stated this in clear terms.
The next one was another Cadet firing a service rifle on a range without a bolt head. The rifle was hand loaded and fired. The bolt blew and tore off the bottom locking lug but the top lug remained intact. Injuries to face and eyes but nothing lasting. Once again, the cause was obvious. Lack of adult supervision.
We all thought these incidents were a bit coincidental with the fact that certain manufacturers were pushing for their rifles to be taken into service so these little incidents were blown out of all proportion. I have to say that the all-clear was given and to my knowledge, Cadets were still firing .303" rifles with RG55, RL52 and HXP ammo until they got their SA80 rifles in 1988-89 or so.
How do I know this, well until about then, I used to get a call from the training teams (where are you now S/Sgt Cox and Larhu)a week or so before range days and examine 12 or so rifles and Brens as a 'double check' and take my own .303 down so as to make good use of the kind ammo facility laid on!
As for the crazing problems, well, while there was crazing, and I saw some, we used a bore-scope and if 'in the opinion of the examining armourer' it was excessive, the rifle was scrapped. But I never saw a service rifle that exploded because of it! We did have a very good example of it for illustration purposes and a few cut-away barrels at Shrivenham.
I of course don't have every article I've read instantly at hand to post as an appeal to authority so the only way I can discuss this will be on the basis of published scientific fact and investigations of erosion problems with Cordite ammunition.(from AR, DB Miscellany, Nov88, p65)
The following warning came to us from the United Kingdom Liason Office,
Armament Research, Development and Engineering Center, Picatenny
Arsenal, N.J.
"1. In July 1987 a UK MOD ban was placed on the firing of ball rounds
from .303 (cal.) No. 4 rifles in UK service as a result of two
explosions which occurred in the chamber area of the weapons and
resulted in burst barrels.
"2. UK MOD investigations found that the barrel explosions were as a
result of severe 'craze cracking' of the two barrels which were of
indeterminate age and life.
"3. UK MOD have initiated a study into why some barrels suffer craze
cracking and others do not, but results of this are not expected to be
complete for some time, and even then might not be conclusive.
"4. Because, in peace-time, .303 No. 4 rifles are only used in Cadet
units, it has been decided that it is not cost-effective to carry out
detailed examinations of all barrels, particularly as the cadets are
being issued with the new L98A1 Cadet GP Rifle. The firing ban will
therefore remain in force.
"5. Users of the No. 4 rifle worldwide, whether civilian or military,
are strongly advised to have the weapons closely examined for signs of
craze cracking and condemned accordingly. Thereafter, it is recommended
that any barrels which have passed such inspection should be examined
regularly for such signs and condemned if necessary."
Owners of the .303 No. 4 rifles should certainly heed the advice in the
UK safety notice to have them "closely examined" before firing them
again. The examination should be conducted, preferably, with the aid of
a good optical bore-scope, by an experienced gunsmith who is familiar
with the signs of erosion in gun barrels. If there are any signs of
roughness from erosion in the barrel immediately ahead of the chamber,
or any other visible defects in the barrel or chamber walls, then the
barrel should be regarded as suspect and the rifle *should not be fired*
until it has been properly fitted with a new barrel.
First off I have a few questions about your experiance in examining heavily eroded bores.
Sources I'd studied many years ago, including expert testimony in a criminal negligence wrongful death suit, experiments by Hiram Maxim, studies of erosion patterns and craze cracking in Naval gun tubes, arguments in parliment over the effects of cordite on rifle and machinegun bores,etc coupled with personal examination of badly eroded Enfield rifle bores of rifles that made it into circulation here after decades of hard use beyond the control of the British military all lead to some basic conclusions.
1. Cordite propellant as used in .303 ammunition was and remained highly erosive due to high operating temperatures and the chemical make up of its products of combustion, notably Oxides of Nitrogen that degrade into Nitric Acid.
Reduction of the Nitroglycerine content of Cordite MD made it much less erosive and chemically erosive (as opposed to corrosive) than Cordite Mk 1 ,but as Hiram Maxim had said of dangers of degradation and sweating nitro at temperatures over 125 degrees, it was a matter of quantity rather than qualities.
2. As you'd noted craze cracking is a recognized factor, which if found to be significant in inspection of a bore would normally result in that barrel being condemned.
From what I've dug up so far and what I remember from earlier studies.
Craze cracking develops quickly, often with the first rounds fired, gas cutting and chemical erosion can deepen and undercut cracks resulting in either a loss of barrel metal in a more or less uniform manner or a relatively large chunk breaking free to obstruct a projectile.
3. Due to the Lee based Enfield actions' separate bolt head and little enclosure by the receiver ring, excessive pressures are more likely to cause a blow out of a cartridge head or failure of the bolt head than a burst barrel or receiver ring as a Mauser like design would suffer. In this respect a perceived weakness of design becomes a fortuitous benefit in a case of excessive pressures.
Early tests seem to indicate that Enfield barrels are more likely to snap off than split when the cause of excess pressures is a bore obstruction.
4. If gas erosion is in the form of "Washing" the grooves and lands can erode at much the same rate, as opposed to mechanical erosion where lands wear much faster than grooves. I've seen this recently in a BSA 1912 barrel, the grooves appearing very deep and the lands very rounded, the bore at that point grossly over sized.
This phenomena can make it less easy to spot the extent of erosion, or identify low spots and freebore. A Star Gauge would spot it but looking from either end of the barrel it wouldn't be obvious to one who didn't know what to look for.
3. The testimony in the negligence case I mentioned (as near as I can remember a case I read about around 40+ years ago, said the bore of the rifle in question showed a distinctive pattern of erosion. The bore from about three inches past the throat was increasingly over sized for several inches, more so than the throat itself, then narrowed gently till a point about fourteen or more inches up the bore where it returned to more or less normal diameter.
Near as I can tell this pattern roughly coincides with the erosion pattern reported by Hiram Maxim in testing machinegun barrels, though in those tests the damage was more locallized in an "egg shaped chamber" several inches past the leade, probably he was using cordite Mk 1.
From studying the sealants used it appears that if the resins fron Swedish Pitch and asphaltum, mixed with atomised lead, were allowed to build up they partly protected the bore but the length of bore protected and extent of protectin varied greatly according to average number of rounds fired between cleanings and how well the bore was cleaned.
I've seen this coating extend far down the bore. There seems to be a hot spot in the propellant burning and pressure curve that results in increasingly rough surface about 14 inches up the bore of heavily fouled barrels.
The witness testified that the first bullet fired that day had been heated by blowby gases in the oversized portion of the bore, then encountered a roughened section further up, the bullet shed its jacket and the core blew through, leaving most of the jacket stuck tightly in the bore. The victim didn't recognize the danger and fired a second time. The bullet telescoped into the shed jacket and resulting pressures caused the bolt head to fracture, part of the bolt head and extractor entering the victims body and slicing a large vein, he probably died of shock as much as loss of blood, but the injury would have been fatal without prompt surgery regardless.
4.
Again I'm going only by memory, but I recall a letter to a magazine which described the destruction of two No.4 rifles by barrel failure due to craze cracking. As I remember it the rifles had round counts of aproximately 125,000 rounds and 80,000 rounds.
Had I known that some would mis-construe your comments as a claim that there has never been a recorded case of barrel failure due to cordite erosion I'd have carefully put those articles away for future reference, the magazines may still be here I just wouldn't know where to look for them at the moment.
I had intended to obtain some Cordite loaded Mk VII ammunition to use in my 1915 No.1 Mk III, till I began looking into the subject more closely after seeing your comments mis-used.
The bore of my 1915 is in very nice condition with little or no wear and certainly no visible erosion, even on close inspection, the bore mikes exactly .303 with .311 groove to groove.
There are many reasons not to use Cordite in a bore that has seen little if any cordite over the years. The main one being that even in a best case scenario Cordite erosion of the throat limits the type of bullets that the bore can handle with acceptable accuracy.
Second hand quotes from "Sniping in France" indicate that long range accuracy of WW1 sniper rifles was adversely effected by no more than the first 500 rounds of Cordite loaded Mk VII ammunition.
Arguments in Parliment and Hiram Maxim's test results indicated that a heavy machinegun bore would be eroded to the point that effective long range accuracy was ruined by the first 3,000 rounds of cordite loaded ammunition.
Later improvements seem to have extended useful accuracy life to around 10,000 rounds of Mk VII ammunition.
I've seen Vickers barrels quoted as having a useful life of 10,000 rounds when the Mk VII load is given as ammunition type, and other more vague cites of 18,000 rounds but this may have been with Mk VIIIZ.
I would like to know if there was a estimated barrel life for the No.1 and No. 4 rifles when cordite was used compared to when Nitro Cellulose propellants were used. Some Non Cordite US manufactured .303 Ball of WW2 used double base propellants not much if any less erosive than cordite.
Take your time in answering. I'm sure you have better resources for looking up recorded cases of barrel failures than I do.
Edited to add
These barrel and action failures involved No.1 Rifles I would expect, though as usual little detailed information is available as to the exact model, possibly earlier types of Long Lee enfield or even Lee Metfords, and ultimate cause of the accidents. No information on round counts or how long those rifles had been in service.
The Gentleman speaking here does make a good point about word of failures of Enfield Rifles not getting much if any play even in those days when they were a major issue military rifle.
http://books.google.com/books/pdf/De...j-gaOz7NVMPOAgSir .FREDERICK BORDEN. Recently, and the report is most satisfactory from the point of view of the military experts here. They found the same defects which had been discovered here, though not all of them, and all the defects which they discovered had been remedied before this report reached us. Now, I do not wish to say a single word against the Lee-Enfield rifle ; but. in justice to the Ross rifle and to Sir Charles Ross, I think it is only fair for me to point out that since these defects were heralded abroad to the injury of the Ross rifle and for the purpose of criticising the department in some cases, I had an inquiry made as to the Lee-Enfleld rifle. Nobody had ever before heard a word about any defect in that rifle; and yet I have a list here of cases that have happened within the last two years, and I will read some of them:
Barrel burst, one bullet telescoping, another remaining in barrel.
Barrel bulged; obstruction in barrel (two rifles).
Breech burst, either defective bullet or breech not properly closed.
Barrel bulged, endeavouring to blow out pull-through.
Muzzle of rifle expanded.
Rifle burst, probably due to defective bullet jamming in barrel and second shot being fired.
Rifle burst.
Rifle burst. Proceedings of board forwarded.
Barrel burst, detective cartridge.
Barrel burst, due to rifleite cartridge being fired.
Barrel burst, defective cartridge, In two cases.
Striker damaged.
Barrel bulged, bullet telescoped.
Barrel bulged, obstruction in barrel.
Spread barrel near muzzle.
Broken bolt.
Broken bolt, barrel twisted and piece blown out near breech.
Bolt broken and bulge in barrel near breech.
Breech bolt broken and kink in barrel.
Breech bolt broken.
Cocking piece broken.
Breech bolt broken.
Rifle barrel burst at side.
In all the tests of the Ross rifle there has never been a case of a burst barrel.
Mr. BERGERON. What do they use in the Mounted Police?
Sir FREDERICK BORDEN. I think they use the Winchester. I say that during the last year far more defects have been shown in the Lee-Enfield rifle, which has been the service rifle in England as well as in Canada, than have been found In the Ross rifle. I mention this merely to show the House that the discovery of defects in individual rifles of the Lee-Enfield class is a matter of every day occurrence.
Mr. FOSTER. Where did these defects develop?
Sir FREDERICK BORDEN. At the annual shooting, at different places in our
own country, and in rifles which have been regularly issued to the militia. I asked for n report from the quartermaster general in order that I might know whether there was anything like an absolutely perfect rifle.
Mr. DANIEL. What ammunition was used in these rifles?
Sir FREDERICK BORDEN. The same In both—that manufactured at Quebec, which is precisely the same as the service ammunition in England. I merely mention that incidentally, in justice to the Ross Rifle Company and to myself. Now, I do not wish to detain the House, because I assume that this matter will be discussed later on. when there will be much better opportunities of discussing it intelligently after the papers have been brought down. Although the papers moved for are most voluminous, 1 will endeavour to have the return prepared and brought down, so that when the militia estimates out of which these rifles are paid for are reached, we shall be better prepared to discuss the matter than we are to-day, and when my hon. friends will be better prepared to criticise intelligently than they can possibly be today, when they must necessarily base their criticisms largely on rumours published in the newspapers and circulated throughout the country.
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