Enfield action strength

Long branch wrote: Zed wrote: It would be interesting to see how a rifle with front locking lug's would fail. Would both lugs fail at the same time? The long lug on the Enfield is an excellent safety measure for the shooter when it all goes wrong. It would have been more interesting if they had examined the rifle a bit more before starting the shoot. I would like to have seen the bolt lug contact areas blued and tested. It is possible that if the small lug was taking more of the load, it may have initially started the crack over a long period of time. He has another video in which he reads a passage from an original manual. It said that an oiled cartridge produced roughly twice as much force on the bolt as a dry one as measured by a crush guage. The front locking actions tend to be a lot "meatier" than the enfield, so it would be hard to get a good comparison. I don't think that would really be relevant anyway. The point he's making is that the action is plenty strong for service cartridges.

It is interesting that when Ishapore produced the 2A (7.62) and they used 'improved steel' they found that during the proof testing that the action warped and the bolt locked up solid.

This happened with both the oiled-round and the dry round.
When they reverted back to the original steel (as specified for the No1 Mk3) the oiled round still warped the action but the dry-round was OK.
They amended the testing to 'drop' the oiled round test but never actually amended the test requirements.

This is why the 2A & 2A1 use the same steel as the No1 Mk3.

Long branch wrote: The Armourer wrote: It is interesting that when Ishapore produced the 2A (7.62) and they used 'improved steel' they found that during the proof testing that the action warped and the bolt locked up solid. This happened with both the oiled-round and the dry round. When they reverted back to the original steel (as specified for the No1 Mk3) the oiled round still warped the action but the dry-round was OK. They amended the testing to 'drop' the oiled round test but never actually amended the test requirements. This is why the 2A & 2A1 use the same steel as the No1 Mk3. I've never heard that. It was always my understanding that the heat treating process was improved.

The old memory is slipping - the article states that with the 'correct'(original) steel the 2A stand up to both the oiled and dry tests.

An interesting article :

The article covers a host of subjects (and several pages) based around the Indian firearms industry and more specifically the ‘Proof House’, but of particular interest are a couple of paragraphs regarding ‘Enfield’s’.


Extract from “Gun Digest 33rd Anniversary 1979 Deluxe Edition”
Article Author : Mr A G Harrison
Qualification : Former ‘Proof Master’ of the ‘Rifle Factory Proof House, Ishapore, India’

From 1908 to 1950 all military bolt action rifles made at Ishapore were proof tested with a dry-round, followed with by an oiled proof round. The proof cartridge was loaded to 24 tons psi breech pressure, or 15% higher than the service pressure. In 1950 (after the departure, in 1949, of India from British control) the material for the rifle bodies was altered from an EN steel to SWES 48 steel with the recoil shoulder and cam recesses being heat treated. With this change the rifle receivers distorted when oiled proof cartridges were fired. This was discovered when hard and sometimes impossible bolt retraction was experienced. Large quantities of rifles were rejected.
To avoid rejections the authorities ordered discontinuance of the oiled proof round. Therefore from 1950 to the end of SMLE production, rifles made at Ishapore were proof tested with one dry proof only, although the specification still called for both dry and oiled proof. All bolts and bolt heads issued as spares were always proofed with a dry proof round only.

A bolt action rifle similar to the SMLE MkIII*, modified to fire the 7.62mm NATO cartridge, was produced at Ishapore, first in February 1965. The receivers were made of SWES 48 steel (as per the SMLE MkIII*) and with the NATO proof cartridge the receivers were found to distort with both the dry and oiled proof round. The material was changed back to the EN steel so now the rifles stand up better to dry and oiled proof. After passing proof the barrels are impressed with the Indian national proof stamp. The bolt handles and bolt head claws are struck with the crossed flags only.