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Are lee Enfield proofs still valid

08 Feb 2016
@ 02:47 am (GMT)

Michael Rayner

Doing a bit of digging on the subject especially on the No 4's, we probably all read the NRA safety warning basically limiting No4's that were converted to 7.62x51 nato and did not have the original Enfield or RSAF barrel to 3650 bar or about 53,000psi on their ranges, which is why I set my limit at that for my wild cat. Original unaltered enfields were still fine to use a MAWP of 4150 bar or 60,190psi which is overlooked in the panick. Now if you look at the whole newsletter you'll see that their ammunition supplier has changed the loads from 144gr to 155gr so it looks like they transferred the onus to owners to have their rifles reproofed so they could use the new rounds they sell on their range without liability back onto the nra. Now you would think it would be easy to find pictures of converted No4's exploded to be all over the Internet but no you don't. So technically to proof a No4 at 60,190psi requires a minimum mean proof pressure of 5190 bar or over 75,000psi!! On the Internet you'd think the Enfield No 4 is about as strong as butter when clearly it's not. Now the plot thickens with the NRAA( national rifle association of Australia) issuing its own warning on converted No4 to 7.62x51 not using 308 win in them, fair enough you'd surmise but you come to the second part of the paragraph which states all ammunition which exceeds 47,000 cup psi ( I don't know what a cup psi is either as they aren't the same) in these modified actions is not permitted. Their rational is 7.62 nato is rated at 47,000 cup psi (there it is again) and 308 win is 55,000 cup psi OMG. So in the space of a couple of years you've gone from guys firing at pressures up to 60,000 psi with no problem down to something regardless of proof to 47,000cup psi. Where is the evidence, my own gunsmith has down heaps of conversions over decades and decades told me he's never had a problem except when hand loading was involved and the worst that happened was the bolt bent. Now over time and lots and lots of rounds metal fatigue will start to play a factor but you could say that about all rifles why is the Enfield No4 the favourite whipping boy is it because people don't know the difference between a No 1 mk3.
Any way that's basically what I've found officially will keep digging. Might ask a proof house about failure rates


08 Feb 2016
@ 08:39 am (GMT)

Ben Grady

Re: Are lee Enfield proofs still valid
Interesting info Michael, keep it coming.
This might interest you.

Slightly off topic, but I found a digital magazine on line that is a .303 Lee Enfield Special. It is from Man Magnum Magazine in south Africa, cost about $14.50 NZ dollars. 105 pages of articles about the Lee Enfield from their magazine starting in 1978. They only do a digital copy so I spent ages printing each page as I prefer a paper copy. Has an article on the .303 Epps. Anyway just thought a few members might be interested in it.
08 Feb 2016
@ 09:23 am (GMT)

Michael Rayner

Re: Are lee Enfield proofs still valid
No worries, I'm just getting frustrated, at this rate they won't be allowed on anyone's range in a decade. I'm wondering if denying a valid proof mark is legal, all British and European proofing houses recognise each other's proof marks. What gives a club the right to deny the original specification based on someone's opinion and come up with Cup psi lol
If you had a rifle converted or altered by a gunsmith where would you even get it proofed in Australia or New Zealand? As currently my proof marks would be invalid
10 Feb 2016
@ 10:44 pm (GMT)

Nathan Foster

Re: Are lee Enfield proofs still valid
I have put warnings about the older rifles in my books. For example, the Lee is spot tempered for strength at the bolt lugs and lug rebates. The rest of the action is not case hardened. The British instead decided to use the best steel they could obtain at that time and then pay close attention to critical areas. This along with a progression of the design to the final beefed up slab sided variant. And the fact that they did beef up the action does give away some indication that there may have been concerns- unless this happened simply and coincidentally due to the cheaper slab side design.

I have made the mistake of bending / screwing the whole action when re-barreling because the No.4 action was soft otherwise and I was quite young at the time and simply gave the wrench a good heave resulting in something akin to modern art (while the barrel stayed put). It bent and screwed forwards of the lug rebtate at the magazine well.

There is a potential problem with rifles still chambered in .303 Brit bursting from throat wear / cracks after a high round count and particularly with corrosive ammo. Ironically it would be safer to convert these to to 7.62. I have seen the older SMLE rifles converted to 7.62, these were Ishapore rifles, N0.1 MkIII. There should still be a few floating around NZ.

If you put a .308 barrel on a Lee but reamed it to .303 and made sure it had plenty of throat (which is standard anyway), the set up would be akin to Arthur Savage's first rifles, akin to some of the 7.62x39 rifles and when all is said and done, would still be potentially safer than an a worn out rifle with its original barrel- possibly even if someone was to foolishly work up to book max and have a stiff bolt incident. I am not suggesting anyone do this, just wanting to help put all of this into perspective.

I had a No.4 Mk 2 chambered in .45/70 which I loaded near to .458 Win Mag velocities and it never missed a beat. But it never fed right and for reasons beyond the understandings of our physical dimension, I mirror polished it with my stainless polishing tools but did not re-blue it. So I had a bling rifle for a time. Lucky the action is not reliant on case hardening (though the steel would have been quenched during production). It kicked like a .458, pressures were high, thrust was immensely high. I never loaded it to the point of flat primers but I loaded it as hot as anyone would for the Ruger Mk.1 wanting max power. The rifle is now back in .303 configuration and is still going strong.

I do remember some incidents from the culling era in NZ but cannot now remember the causes. It is a pity as a good record of these would help in this interesting discussion. Plugged bores would not have been uncommon during those times. Apart from the few culling blow ups (I remember one shooter lost his jaw from a bolt coming back in a No.1 MKIII), I cannot remember any major incidents with the Lee rifle. Even the case to bore ratio of the .303 cartridge (like the 8x57) can help prevent us from suffering severe consequences such as using H4895 / 2206 by accident when we should have been using Varget / 2208.

One of the areas where Mauser trumped was in the third lug, also making sure that this lug floated to ensure it was a secondary line of defense.

I think also we have to be realistic in that all actions will reach a point of rupture. The big question is- how will the action break down if it does rupture. Few people think about this. For example, if a Tikka ruptures or worse still one of these custom shop jobs with extra milled cuts, the whole action can be like a grenade. On the other hand, that 'weak' Swedish Mauser (without a third lug) can break down with some dignity.
11 Feb 2016
@ 12:37 am (GMT)

Michael Rayner

Re: Are lee Enfield proofs still valid
Thanks Nathan, I'm starting to come round to what the NRA were thinking when they have all these converted rifles turning up, I guess they needed to put a line in the sand somewhere. Especially when people were deliberately putting tight bores on their rifles to get longer barrel life it immediately invalidates the proof when you change barrels anyway. So when their supplier changed the ammo they've had to put a stop to it. Still don't know what the NRAA is on though.
I'm trying to work out where to stop on my own action and wild cat. Being a cylinder shape case body, thrust is more outwards which lowers bolt thrust, 303 is a wedge shape so wants to thrust backwards towards the weakest point. It's probably why the 45-70 did so well in your No4.
So the question is do I stop worrying about what quick load says the pressure is and just go on pressure signs from the case like I would normally do to find the limit and then back it off once I've found it. I'm honestly not expecting to be able to go to much more as the case walls are very thin after the fire forming, so far the cases that I used for the latest round of testing are on have had their 4th firing with no splits or loose primer pockets. Quick load reckons I'm at about 50,600 psi for a 150gr at 2906 fps
11 Feb 2016
@ 01:31 am (GMT)

Nathan Foster

Re: Are lee Enfield proofs still valid
Well lets say you are using NNY stamped brass (very soft) and Winchester primer (also very soft). These will let you know well in advance before the action ruptures or even before the bolt gets very stiff. So these are things you can do as an extra measure of caution if you prefer.

You may as well stop at 2900fps. This is plenty of speed. The best thing you can do from here is look for SST availability. Bullet choice is so important, velocity can only give us so much as you know. At this speed, the rig will be very hard hitting out to quite a distance. Furthermore, if you open up the meplat on the Sierra Matchking and if it shoots straight, this particular bullet (others please do not look to the SMK for hunting in general as this is unique) will get you well out. Call it quits at 1800fps impact velocity. Thats a long way for a regular .303 let alone an imp.
11 Feb 2016
@ 04:09 am (GMT)

Thomas Kitchen

Re: Are lee Enfield proofs still valid
not sure how true it is but someone once told me elwood epps did a lot of testing to see how much pressure the lee enfield would take. i havent been able to verify but from my understanding he found that the action would stretch more then explode letting the pressure out around bolt face.

have heard if you constantly run high pressure you can slow stretch action and set bolt back a bit???

thing is to load for accuracy while checking for pressure.

from my understanding the ishapore 7.62x51 was not a conversion but a new build modified for 308win, i remember seeing these on the news in the mumbai terrorist attacks thinking holly hell not sure i would be keen to take on a terrorist with a 303. luckily the are not for front line service and the black cats are bit more equipped.
ishapore also had a single shot 410 (not the modern 410) conversion for crowd control.

its a long history the lee enfield with so many variables its hard to get concrete data for them.

hmm i got a spare no4 action here and i know can west does a 3 shot 45-70 magazine i better stop reading Nathan comments they put bad ideas in my head ha ha
11 Feb 2016
@ 06:21 am (GMT)

Michael Rayner

Re: Are lee Enfield proofs still valid
That's part of the problem it's always someone told me he heard from someone, or I heard through the grapevine. There's very little hard documented evidence with an organisation willing to put there name to it apart from the 2 I've mentioned.
So here's the question if you had an all original unaltered proofed No4 7.62 NATO would you still run it around its MAWP (maximum average working pressure) of 60,190psi?
Like you Thomas I've heard they stretch too, that's one reason why they have different size bolt heads. What I could do is get the gunsmith to check the headspace now and see if I can get up to the estimated 53,000 psi on quick load with my 174gr load which would be 2752fps @ 52,724psi and bang on node 5 that would make me very happy to hit that. Then after a few rounds down the tube take it back an remeasure and see if it has stretched.
Interesting note for my 150 gr load at 2906fps, QL Predicted 2911 fps only 5 fps out. QL also reckons accuracy node is back at 2811 fps bugger!! To get to the next node I'd need to be doing 3023 fps @ 57,203 psi!! DONT WORRY I won't be trying that I'm not that Mad. But definitely Re17 is fantastic in this wildcat low apparent pressure considering velocity
11 Feb 2016
@ 08:19 am (GMT)

Mike Davis

Re: Are lee Enfield proofs still valid
Nathan Ive read just about every hunting book ever published here in N.Z. and the cullers did have a few incidents........most were with hangfire ammo,they would be into a mob and get click start working bolt and boom would throw bolt out back of action.the other one that stands out was a certain Mr Crump was know to go through a fair few rifles as the actions has siezed......caused by putting rifle under water and shooting trout!!!!!!!
read that one from a few different places.
I know of a chap who wanted to blow up a .303 action for demonstration purposes,they plugged barrel with dirt twice and it cleared it self then tried dowel,same thing,in the end they threaded a bolt in muzzle...that wrecked it,cant remember if it split barrel or destroyed action .DONT TRY THIS AT HOME.
15 Feb 2016
@ 10:30 pm (GMT)

Michael Rayner

Re: Are lee Enfield proofs still valid
Was very fortunate to hear back from a proofing house, while I can't disclose what was in the email as its confidential. It gives me confidence moving forward with my plans.
16 Feb 2016
@ 03:57 am (GMT)

Michael Rayner

Re: Are lee Enfield proofs still valid
I've found some more info in Stephen Redgwell's book I found on Google books about a wildcat called a 303 ICBM designed by three Kiwis Crawshaw,Bunn,Munt in 1997. Anyone know them, or about it. Running some of there loads through my program and they would have been running around 60,000 psi maybe more for their top loads. Wondering if any of their rifles survived and still going


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