Gallery of Dramas. Broken Enfield Parts!

[Claven2]

nother photo surfaced:



I now think the faliure originated on the left side lug, which broke completely off, and then propagated to a stress point at the base of the safety lug. Uneven bearing could be the culprit, IF it was VERY bad and the load was hot.

[Peter Laidler]

Although we can't see the grain structure too well, I agree entirely with clav. Uneven bearing, whole load taken on l/h lug and something's got to give. Mind you, is that a penetrative oil staining at the left and right hand end of the broken lug? Or is it some camera shading? If it's oil staining, it indicates an earlier fissure which would back up Clavs observation that it's an uneven bearing over a period until.....................

GREAT student projects.................

Are you non-too-technical forumers enjoying this thread discussion as much as the technical bods are?

[vintage hunter]

Comparing the photos to the earlier ones of a sheared left lug it appears that the fracture on this one actually started towards the top of the lug and travels down through it at an angle leaving part of it still attached to the rear half of the bolt body. Weird.

[paulseamus]

Could a partially closed bolt, from shallow set primers, also contribute to an uneven loading on the two locking lugs?

[Peter Laidler]

It COULD be in theory Paul but due to the inbuilt mechanical safety, you cannot actually fire the rifle until the bolt is positively locked. On the reverse side to that and thinking about it, you couldn't replicate the situation by half opening the bolt AFTER firing because you can't unlock the bolt until the pressures have dropped to atmospheric

[RangeRover]

Are you non-too-technical forumers enjoying this thread discussion as much as the technical bods are?

This non-too-technical forumer is definitely enjoying this thread discussion. I hope to never add any pictures or personal experiences to the thread but it's great to have access to the more expert dialogue being shared about what things can go wrong.

[Brian Dick]

In all my years and hundred of Lee's through my hands, I'd never seen anything like it up until Claven's post. Thanks.

"Just a couple more grains of powder ought to do it there Jethro!"

Regards,
Brian

[Peter Laidler]

Is that the same bolt from a different angle Brian? If not, it's a remarkably similar/identical fault line. Can we have a pic of the broken surface? Thanks.

[vintage hunter]

Seeing these bolt failures in Enfield no.4's brings to mind the number of Colt SAA's chambered in .44 Special and .45 Colt that Elmer Kieth blew up while developing the .44 Magnum cartridge and the bolt lug failures of M1 Garand and M 14 match rifles experienced by shooters who used increasingly hot handloads in the attempt to improve the long range performance of the .30-06 and 7.62 Nato rounds for competition shooting. I'm no metallurgical engineer by any means so I could be wrong here but I think the Enfield bolt failure problem is directly related to shooters who are foolishly ignoring the mechanical limits of the firearm in question in the attempt to gain improved ballistic performance. Looking at the admittedly untested load data that is available over the 'net will support this theory, based on published MV's, if this data were to be pressure tested in a ballistics lab the results would surely show that they are quite a bit beyond what the gun can withstand. In other words, some people are trying to make a bob cat roar like a lion.

[Brian Dick]

Peter, It's the same bolt photographed from the top and the bottom. The lugs were obviously bearing evenly, eh?

Can you imagine blowing up your new No.4Mk2? I do reload for the .303 but it's been a while as I just don't have the time these days. I'm a boring reloader though, still using IMR 4895 loads worked up by my first mentor in the gun trade when I was growing up in the gun and pawn business in Florida. He was a US Army, (Korea), U.S. Air Force, U.S. Border Patrol, Secret Service, and Treasury Dept. veteran and taught me how to do it right with quality, not quantity. Safety was always top priority. He taught me how to shoot too and his loads will still group as good as any ammo available in my old rifles. ATB, Brian