More Bad Press For The Enfield

[Surpmil]

>>>1. The more tapered .303 case presumably puts more pressure on the bolt and receiver than the more parallel-sided 7.62mm case?<<<

Why do you presume that?

I should rephrase that to say "given an equal case contact area and charge".

I understood it was generally recognized that the more steeply a case tapered, the less adhesion to the chamber walls. Is that not correct?

[Edward Horton]

I should rephrase that to say "given an equal case contact area and charge".

I understood it was generally recognized that the more steeply a case tapered, the less adhesion to the chamber walls. Is that not correct?

Surpmil, you are 100% correct and didn't "presume" anything

.303 Improved Epps

The 303 British suffers from "droopy shoulders". Good in its day, the shallow angle was designed to help in loading and placement of the long stranded propellant "cordite", within the case. While good for factory production then, it's a real problem for the reloader today.

Any cartridge with shallow shoulders is more prone to case stretching, case wall thinning and thickening around the neck. Maximum loads fired from these cases accelerate the process.

Canadian gunsmith Ellwood Epps saw the problem and corrected it. He knew that steeply angled shoulders helped modern spherical and extruded powders burn more within the case and less up the barrel. His solution was to increase the shoulder angle to 35 degrees from 16. At the same time, he decreased the body taper by over 50 thou. The resulting improved cartridge showed a 15 % velocity enhancement over the standard 303 British when fired from the P-14.

After consulting with PO Ackley, Mr Epps reformed the cases with minimal body taper and sharply angled shoulders. Reduced body taper lessens the rearward pressure effects on the bolt and lugs (bolt thrust). Sharp shoulder angles inhibit forward brass flow, which reduces the need to trim cases as often.

Originally, the improvements were made to increase brass life, not to produce a higher velocity round. Mr Epps knew that reshaping the case into a more efficient design would yield this secondary benefit, but considered improved case life to be the most important factor.



303 Epps - Notes on Improved Cases

[jmoore]

Perhaps you are thinking of fatique, aluminum and the DeHavilland Comet? de Havilland Comet - Wikipedia, the free encyclopedia

No, although it was a big story.

Not being in school at the time I am not certain pre WWII design practices. However, I am looking at my 1941 edition of Modern Metallurgy for Engineers, on page 152 is a very nice S-N curve for carbon steels, and it is dated 1921. On page 153 is the relation of enruance limit to tensile strength and brinell hardness, and that is dated 1929.

At least for carbon steels, fatique lifetime was well defined and understood.

Actually I was fishing for another early reference, and a sometimes making a "disprovable" statement is the easiest way to learn something. I don't mind being stupid...

Now, I'll be off to look for another used book!

[Alan de Enfield]

The letter which I wrote (see below) either didn't get there in time for this issue or was disregarded in favour of the following.
It appears we have a 'new contibutor' - who seems to know a thing or two about Savage rifles :

From May 2010 issue (which arrived today)

I plan to write back in response to Mr Whites "riposte" i the April issue of the magazine.
I will be using the information provided by Peter Laidler, and the up-to-date information from 'strangely'.

Here is my proposed letter :

Dear Sir
In the letter pages of the April issue, Mr Chris White issued a “Riposte” in response to the several letters concerning his article “Wet Weather Drill” (March issue).

Yet again Mr. White is perpetuating internet rumours and myths without taking the trouble to actually investigate and substantiate his comments.

His two main arguments seem to revolve around :
a) “…. The MOD placing an embargo on cadets shooting No4’s ….”
b) “… the NRA issued Safety warning ….”

Having investigated both of these statements it is now clear that they are both gross misinterpretations of fact, so what is the actual truth behind them ?

a) The rumour of the Mod ‘banning’ the use of No4 Lee Enfield’s has come about as a result of a cadet being injured by an “Exploding” rifle.
The facts are as follows :
“The Board of Enquiry after the event found out what happened and it was this. The rifles that were 'live' were taken onto the firing point and a couple of other 'live - serviceable' rifles were at the back of the firing point together with a few DP rifles, used for what is called 'background activity' One of the rifles on the firing point wouldn't fire so the instructor stood behind the firer took it off him, cleared it and shouted to one of the Cadet NCO's at the rear.... 'bring me another rifle over.....' which he did.

What neither of them did was to check that the 'new' rifle was serviceable....., and in this case, it wasn't because it had a big hole through the barrel, top to bottom. BUT, the BOLT was serviceable, unlike the bolt in the rifle that had failed to fire, The first round it fired resulted in the accident where the Cadet lost a couple of fingers.

The Board of Enquiry established that prior to the actual shooting, half the group had sat around in a circle and started to clean the rifles and bolts while the other half had filled some Bren magazines and cleaned/oiled the Bren guns. Then they changed over and the Bren filling half finished off cleaning and oiling the rifles and assembled them.

Unfortunately, due to 'lack of adult supervision', a DP bolt with a welded up bolt face and therefore no striker protrusion was placed into a service rifle. This rifle wouldn't fire. But because of this, a DP rifle went onto the firing point with a serviceable bolt and fired”.

As you can see the failure was not due to the rifle, but due to a massive failure of safety rules and supervision.


b) “.. the NRA Safety warning …” Indeed the NRA did issue such a warning, but (unlike Mr White) have actually undertaken investigations and have now withdrawn the warning. The comments now published in the ‘Journal’ say :

“After further consideration of all factors influencing safety of these conversions and consultation with the Birmingham Proof Master, the following advice must be adhered to in respect of the use of Enfield No 4 conversions:


• Conversions retaining their original Enfield barrel or a replacement barrel as manufactured by RSAF Enfield are safe to use with commercial CIP approved ammunition, which complies with a MAWP of 4150 bar, loaded with any weight of bullet, providing they carry a valid proof mark, and are still in the same condition as when submitted for proof.

• Conversions fitted with any other make of barrel, (such as Ferlach, Maddco, Krieger etc) should be checked by a competent gunsmith to determine the throat diameter of the chamber/barrel fitted before use.

• Conversions, where the throat diameter is less than the CIP specification of 0.311” but not smaller than 0.3085” must not be used with ammunition which exceeds 3650 Bar MAWP when fired in a SAAMI/CIP pressure barrel.

• Conversions which have been checked and found to comply with Rule 150 may safely be used with any ammunition supplied by the NRA including the 155 grain Radway Green Cartridge, 155 grain RUAG Cartridge or any other commercial CIP Approved cartridges loaded with bullets of any weight provided that the ammunition pressure does not exceed 3650 Bar when measured in a CIP standard barrel”.

Surely it is now time to put this argument “to bed” and for Mr White to stand up and admit he has been proliferating unsubstantiated rumours.

Yours faithfully

[Surpmil]

And what is "Rule 150" again?

[Mk VII]

Defines the specification for TR rifle.

[Strangely Brown]

The 2010 Bisley Bible is available online for the first time here:

National Rifle Association of the UK | NRA | News | All

TR – Target Rifle
150 Any bolt-action rifle which, in the opinion of the Shooting Committee, is
of conventional design and safe. All rifles must also conform to the following:
General: The rifle or all its component parts must be readily available in
quantity.
Weight: Maximum 6.5kg (14.32lbs) as used including all attachments except
the sling.
Barrel and Chamber: Suitable for firing any of:
a the standard 7.62 x 51mm NATO military cartridge
58 FIREARMS, AMMUNITION, EQUIPMENT and TARGETS
b the .308” Winchester commercial cartridge
c the .303” British Mk VII military cartridge
d the standard 5.56 x 45mm NATO military cartridge
e the .223” Remington commercial cartridge
Note: (a) and (b) are not necessarily the same, and (d) and (e) are not the same.
Attention is drawn to Appendix V.
Bore and Chamber Dimensions: The dimensions must not be less than either CIP or SAAMI minimum chamber drawings (whichever is the smaller) other than in (a) and (b) above where the following concessions are permitted:
the bore diameter must not be less than 0.298”.
the groove diameter must not be less than 0.3065”.
the throat diameter must not be less than either the bullet diameter or
0.3085”, whichever is the greater.
the minimum throat length may also be reduced but only to such an
extent that the bullet of the cartridge in use is not in contact with the
rifling. See Appendix V Para 7f.
If reduced bore or groove diameters as above are used, only ammunition
developing an average max pressure less than 3650 Bar under CIP test conditions may be used. NRA ammunition “as issued” will satisfy this limit.
Pull of trigger: Minimum 1.5kg (3.307lbs). Set triggers and ‘release’ triggers
are not allowed.
Stock and Butt: May be shaped so as to be comfortable to the firer. A thumb
hole for the trigger hand is permitted. Adjustable butt plates without hooks are
permitted. The depth of the butt plate curvature shall not exceed 20mm (0.79”)
at its deepest point. A hand stop is permitted.
Magazine: If fitted shall not be used except as a loading platform for single
rounds.
Muzzle brakes: Not allowed.
Sling: Must conform to Para 209.
Backsight: A variable dioptre eye piece or single correcting lens may be used
(but see Paras 206 and 207). One or more optically flat filters may also be used
in front of or in rear of the aperture. A flexible disc or eyecup may be used. In
addition a piece of fl at material or a blinder may be fitted to the backsight to
restrict the vision of the disengaged eye.
Foresight: Any type which may contain a single clear or coloured magnifying
lens which has a minimum focal length of 2 metres (0.5 dioptre) but see Paras
206 and 207. It may also contain optically flat clear or coloured element(s).
Spirit levels: It is permitted to attach spirit levels or other level indicators to the
rifle.

FIREARMS, AMMUNITION, EQUIPMENT and TARGETS 59
Overseas competitors. Where reciprocal agreement has been reached, overseas competitors may use, in competition, target rifles which conform to their home country’s Governing Body’s rules, during their first three months in the United Kingdom, provided that they conform to the maximum weight, chamber dimensions, minimum trigger pull and sight specifications given above. Out of competition only the minimum trigger weight condition must be complied with.
Telescopic sights are not permitted. The rifles must be suitable for use with any ammunition supplied by the NRA (see Appendix V).

[Dimitri]

Oil and water on your ammunition and in your chamber can increase the wear and head space on ANY rifle, BUT it does not cause the Enfield Rifle to explode.
(Just ask your veterans who fired them under wet combat conditions)

The L42 rifles were used for a number of years and I doubt anyone issued one had them explode. So I doubt there is any proof the magazine could give.

If you work at it, its possible to "grenade" any firearm action. Seems that I've heard of plenty more Mauser derivatives letting go over the years than Lee types.

Camp Perry over the years has had many Mauser actions go as competitors attempted to get 300 Win Mag velocities out of the 30-06. Per Gale McMilan.

If I may make a suggestion, the Canadian members here could try and contact Jim Bullock he was on the Canadian shooting team and also pressure tested thousands of rounds of ammunition.

I purchased my Envoy (E20) from him. Only thing he told me to worry about is that the rifle bore is slightly undersized and I should back the powder down by one grain. Otherwise he didn't tell me anything else like worrying about rain.

Dimitri

[Edward Horton]

Dimitri

I have a small collection of 12 Enfield Rifles and I'm Pro-Enfield and do NOT think the Enfield rifle has ANY inherent weaknesses.

On the other side of the coin I'm anti-oiling or greasing cartridge cases because it increases bolt thrust.

The Enfield rifle was proof tested with an oiled cartridge and then checked with a .067 head space gauge. If the bolt closed on this .067 head space gauge the rifle failed proof testing due to excessive bolt lug and bolt head set back. (a oiled proof cartridge exerts more bolt thrust than a dry proof cartridge)

The Australians when testing .303 Enfield's converted to 7.62 NATO used a .303 enfield as a "control" for the 7.62 testing. The control .303 Enfield fired six .303 proof test rounds and the headspace increased by .010.

Water,oil or grease in the chamber or on the ammunition increases bolt thrust and the wear and tear or serviceability of your Enfiel rifle. The issued Enfield rifles were inspected four times per year, three mini-visual inspections and one complete tear down inspection.

We know the Armourers replaced bolt heads and bolt bodies during these inspections and dry firing doesn't cause excess bolt thrust.

If shooting and bolt thrust causes increased head space, then oil or water on your ammunition or in your chamber and the added bolt thrust isn't going to make your Enfield last longer.

[Surpmil]

....The Enfield rifle was proof tested with an oiled cartridge and then checked with a .067 head space gauge. If the bolt closed on this .067 head space gauge the rifle failed proof testing due to excessive bolt lug and bolt head set back. (a oiled proof cartridge exerts more bolt thrust than a dry proof cartridge)

I have a little difficulty with this. Is it being claimed that every No4 rifle sent for proof had a bolt head fitted that just closed over the .064 gauge? I rather doubt it. Perhaps a feeler gauge was used with the existing bolt head and the .064 guage and if "set back" of more than .003" occured, THEN the rifle failed proof?

The Australians when testing .303 Enfield's converted to 7.62 NATO used a .303 enfield as a "control" for the 7.62 testing. The control .303 Enfield fired six .303 proof test rounds and the headspace increased by .010.

I'm afraid I'm a bit sceptical about tests like this as well. Official "tests" have a funny way of producing the result that the authorities want, or that 'interested parties' want. (I've cited a few examples elsewhere concerning Canadian-produced equipment) We've been told here by informed parties, that the Indian No1 Rifles in 7.62mm are built of the same steel that UK and Australian No1 Rifles were built of. Of course, we've also been told that 'better' steel was used, but the weight of authority lies with the former opinion if I remember the parties involved.

Water,oil or grease in the chamber or on the ammunition increases bolt thrust and the wear and tear or serviceability of your Enfiel rifle. The issued Enfield Rifles were inspected four times per year, three mini-visual inspections and one complete tear down inspection.

We know the Armourers replaced bolt heads and bolt bodies during these inspections and dry firing doesn't cause excess bolt thrust.

If shooting and bolt thrust causes increased head space, then oil or water on your ammunition or in your chamber and the added bolt thrust isn't going to make your Enfield last longer.

Perhaps it's not your intention to suggest that bolthead and bodies were replaced on a regular, or even annual basis, but that's how it reads to me. Just thought I'd mention that.