The quality of steel in war production no4s

[303Guy]

I can't see the MLE action body or bolt being weaker than the SMLE

I concur. If anything the MLE's were/are stronger. Apparently the same steel specs were adhered to. Only the Ishaporian 7.62 NATO rifle used modern alloy steel. My 1902 MLE withstood nearly 500 rounds of MkVIII machinegun ammo without disintegrating. Admittedly it was a long time ago and the steel may have aged some since then ....

[Peter Laidler]

Who told you that the Ishapore 7.62 No1 rifles used modern alloy steels 303 guy? Some were simply converted from their previous .303" spec and the new-build were made using exactly the same steel mix - or certainly within the permissable paramaters.

[303Guy]

Now that you ask, I don't recall. There was a discussion somewhere where that came up. I recall it being authoritative but not the actual source. Anyway, a quick search found the following in Wikipedia.

There were other differences to the Ishapore 2A/2A1 rifles that include the use of improved steel (to handle the increased pressures of the 7.62mm NATO round), and a redesigned extractor to cope with the rimless round.

I believe it because the No4 can handle the 308 while the No1 cannot and the only real difference in the strength of the two is in the steel. That info came from a now deceased ex-armourer/gunsmith. He told me the No1 action would develop excess headspace when chambered in 308. I don't recall the details but he said someone tried it, I think as a test. I don't think it was he but rather it was at a place where he was - not sure now.

[Peter Laidler]

The increased pressures were negligeable. I think it was 18.5 over 19 t/Sq" proof load at the time - using the same method (someone/Tony E/Bruce in Oz...) please feel free to correct me with the loads if I'm wrong. We analysed the steel structure between them as an interesting or relevant student project and there was no discernable differences at all. I wrote up a long paper on this a couple of years ago. Common myth that has perpetuated itself I'm afraid to say.

[303Guy]

Well well! Is it possible the Indians were using a stronger than original spec steel already so no changes were needed? On the internet we find circular references with no reference source so it could be hearsay/myth that's been quoted as fact as you say. There is that niggling thing my uncle told me about the 308 modified No1 that set the bolt back (not a quick process but how many shots it took I don't know - I don't think he knew). Well, there must be a way of finding out for sure.

My understanding (which is open to correction) is that proof loads were 25% above normal and three such loads should not set the bolt back measurably. That would be a little above 7.62 NATO loadings but how many shots would a rifle operating close to its strength limit withstand? I don't know. It is said the No4 is a stronger action - strong enough to handle 7.62 NATO but with a smaller safety margin than a purpose built 7.62 NATO.

We know what the original steel specification for No1's and that strength is known as is the 4140 used in No4's so we have some sort of comparison. I don't know so I can't do the comparison.

In the meantime I'm going to erase what I thought was fact until proven otherwise.

[Thunderbox]

Well well! Is it possible the Indians were using a stronger than original spec steel already so no changes were needed? On the internet we find circular references with no reference source so it could be hearsay/myth that's been quoted as fact as you say. There is that niggling thing my uncle told me about the 308 modified No1 that set the bolt back (not a quick process but how many shots it took I don't know - I don't think he knew). Well, there must be a way of finding out for sure.

My understanding (which is open to correction) is that proof loads were 25% above normal and three such loads should not set the bolt back measurably. That would be a little above 7.62 NATO loadings but how many shots would a rifle operating close to its strength limit withstand? I don't know. It is said the No4 is a stronger action - strong enough to handle 7.62 NATO but with a smaller safety margin than a purpose built 7.62 NATO.

We know what the original steel specification for No1's and that strength is known as is the 4140 used in No4's so we have some sort of comparison. I don't know so I can't do the comparison.

In the meantime I'm going to erase what I thought was fact until proven otherwise.

The "stronger steel" comment originated in Edwards' book about "Indian Enfields"- but that book was written without any cooperation or data from the Indian authorities or from the Ishapore factory.


Proof loads are nowhere near the actual strength limit of the rifle. The No1 rifle is thought to be about ten times as strong as required by the the service load. The Textbook of Small Arms notes that No1s can withstand several 30T proof firings without any effects - thats more than 50% over the current .308W/7.62x51 proof test...

[Ridolpho]

This thread continues to evolve! Don't you love it when an undocumented myth (better quality steel in Ishapore 7.62 rifles) becomes entrenched in the literature. There do appear to be two documentable observations however: 1) Lithgow No. 1 rifle conversions to 7.62 were tested and not found satisfactory, terminating the program (S.A.I.S. No. 19, Skennerton and Labudda, pg. 21,22) and 2) Many thousands of 7.62 No. 1 rifles were manufactured by Ishapore. Did the Indians simply choose to accept or live with the problems found in the 1000 round test rifles at Lithgow? Has anyone out there found severe headspace problems or small cracks (as described for the Lithgow test rifles) in well used 2A/2A1 rifles?

Ridolpho

[Peter Laidler]

I really don't believe that the Lithgow project to convert SMLE's to 7.62mm was anything more than what we call a 'look-see' development. And all that welding steel on the sides etc etc to reinforce what I ask? Anyone else think that they look like an amateur effort as opposed to true factory toolroom project. The L1A1 project was already agreed, funded and well in hand and additional machinery was already on its way ex Fazakerley. Nope........ Just doesn't ring true. And we already know from hindsight that the rifle was well capable of taking the extra load. Just my view of course looking at it from the bleedin' obvious point of view.

[ssj]

Who told you that the Ishapore 7.62 No1 rifles used modern alloy steels 303 guy? Some were simply converted from their previous .303" spec and the new-build were made using exactly the same steel mix - or certainly within the permissable paramaters.

From what ive read elsewhere the Ishapore receiver was a higher grade of steel, you are the first ive read to say no....this place is turning into a real gold mine...thanks
;]

[303Guy]

I've found where the 7.62 NATO conversion on SMLE's were done - Lithgow Australia. The tests were done on degraded rifles in which the action bodies were replaced with plain carbon steel bodies. Note the mean proof load pressure.





---------- Post added at 02:25 PM ---------- Previous post was at 02:15 PM ----------

This is the source of those pages;



I 'borrowed' these from another poster on another forum (I hope he doesn't mind - I didn't ask him).