Post mortum LE bolt failure...

[ssj]

Hi,

Ive seen the result of a barrel blocked with ice...the guy was walking along and put the muzzle through snow, it froze in and when he fired it peeled like banana, the chamber though held....it is a lot thicker after all. Ive seen a few bulges and breakes as well, all after the reinforce Im all eyes if someone shows me a chamber failure...!

Im going with a bad hand load as well, Im currenty loading 39.5gr for 174 and 37.5 for 150gr and the max listed is about 43 for adi 2208, how you get much more in I dont know the case looks pretty full at 39.5. Ive asked for more pics incl cases....and if the serial numbers matched. One thing Ive noticed with kiwis that gives me the sh**s is their "it will be alright attitude" and let buyer beware....I'll also ask what powder he used....he says he checked the barrel was clear btw.

[303Guy]

The reason I suggested a blown primer is that I have recently read a report of a cocking piece being driven into a shooters eye caused by a blown primer. I recall he lost his eye! (Must double check that. Was that on this forum?)

Another one;

... a .303 primer and had the No4 Enfield reset to full cock----after it blew ...

5thBatt, the reduced charge detonation is called SEE for secondary event explosion. The description of events is that there is insufficient powder to build up pressure and while it ignites OK as the bullets moves forward it increases volume which reduces pressure to the point where combustions slows down and the bullet stops. The powder is still burning and now builds pressure very rapidly behind the now stationary bullet which can't accelerates away fast enough and the powder explodes.

Only some powders are prone to this under certain conditions. AR2208 (Varget) is not one of them. The worst one can do to overload a 303 with AR2208 is create a 308 load which has a compressed charge at max load. Other powders are different.

A reload with no powder can leave the bullet in the throat and with the slam loading of the cock on closing can push the bullet of the fresh cartridge back into the case doing three things; reducing powder volume an doubling the bullet weight plus misaligning the second bullet! . I use a case filling powder to prevent the bullet from being pushed back. I also have a routine of standing all cases upright in a reloading block and shining a light down each case to inspect the powder charge - no exception! I never powder then bullet a case.

With this rifle the report says the shooter noted one heavy load with the full power loads and the last shot blew the cocking piece into his glasses shattering them.

"Prepared it for firing and put some light hand loads through. Stoked with the results I decided to test it against some factory ammo. First round gave a hell of a whack, sticky bolt but no hard extraction or real issues. Thought to myself they must have overcharged that one. Chambered the next something didn't feel right. Had a good soldiers 5 and nothing I could see wrong. Had a shot, crack, safety glasses smashed, bloody sore head and a shattered bolt. It snapped just forward of the bolt handle and sent **** flying everywhere. I've got a few garks on my trigger hand and forearm on the other. By my account I'm lucky to have walked away from that. "

Consider that the area behind the lugs are being stressed by the stress concentration at the junction of lug and bolt body (there is an illustration of these stresses out there - if I can find it I'll post the link) during firing so a severe blow could fracture the bolt at that point rather than further back. It sounds like something was damaged on the first shot. The second shot blew more than the bolt rear off - the shooter got stuff in his shooting hand and left forearm. That second shot was over pressure and the case ruptured! There was no bullet left in the throat.

[mrbungle]

here is a chamber failure. not a enfield but a M-14 , the whole damn thing exploded... with split chamber.

http://www.thegunzone.com/m1akb.html

[ssj]

here is a chamber failure. not a enfield but a M-14 , the whole damn thing exploded... with split chamber.

http://www.thegunzone.com/m1akb.html

Fasinating report on it as well....good indicator not to use a no name barrel....

http://www.thegunzone.com/m1akb/762r.html

[Thunderbox]

The reason I suggested a blown primer is that I have recently read a report of a cocking piece being driven into a shooters eye caused by a blown primer. I recall he lost his eye! (Must double check that. Was that on this forum?)

I think we all agreed that story was probably rubbish. If you think about it, primer gases blowing back into the bolt would act on the face of the firing pin - driving the firing pin back. I don't think anyone's heard of a primer doing more than half-cock - because the primer lacks the energy to compress the firing pin spring any further. If a primer were to compress the spring further, then it would simply come to a point where the spring is solid (i.e. not much past full cock). The primer gas would then have to have enough energy to shatter the end of the bolt body, so that the striker, pin and spring can carry on going backwards to get anywhere near a shooter's eye. I don't think that has even happened when someone has fired a rifle with no bolthead fitted, and the main propellant charge is free to exit rearwards.

You have to be wary of stories about shooters being injured whilst firing Enfields. Mostly they seem to be urban myth. I'm not aware of a any that have been proven, let alone with a standard rifle firing standard ammunition.

[browningautorifle]

I've had lots of blown primers with questionable ammo in Lee Enfield's of various types. I've never had any action as result, none at all.

[ssj]

Comment on the "light" load used,

"The load is based on Ed Harris' "the load", which is 13gn of Red Dot. I put a .311 sized GC165gn hard cast pill on 13gn of AS30N primed in CCI #200 primed cases trimmed to 2.22. "

ho hum....

Alliant Powder - Reloader's Guide

Red Dot a cowboy (LOL) pistol load.........

Ed Harris articles for reduced loads in Reloading and Ammunition Forum

Never the less, a braver man than I.

[303Guy]

... primer gases blowing back into the bolt would act on the face of the firing pin - driving the firing pin back.

It's not the primer gasses, it's the main charge gasses and those would act on the firing pin collar.

I might be referring to the same event ssj is talking about in which case his eye was not damaged. I'm looking for that post so I can get my facts right.

Pierced a .303 primer and had the No4 Enfield reset to full cock----after it blew past full cock and raked the sear bent over my thumb.

And the No4 has a working gas vent in the bolthead! So here we have more than the half-cock that is said to have been observed by our members here.

The story I mentioned might be urban myth but here we have photo's of a broken bolt with a report that the rear piece struck the shooter in the face. That rear piece is reasonably heavy so the forces involved are considerable. The shooter said it hurt his face.

... bloody sore head ...

He also said he had injuries to his right hand and left forearm so there was a blowout.

I've got a few garks on my trigger hand and forearm on the other.

[bigduke6]

Comment on the "light" load used,

"The load is based on Ed Harris' "the load", which is 13gn of Red Dot. I put a .311 sized GC165gn hard cast pill on 13gn of AS30N primed in CCI #200 primed cases trimmed to 2.22. "

ho hum....

Alliant Powder - Reloader's Guide

Red Dot a cowboy (LOL) pistol load.........

Ed Harris articles for reduced loads in Reloading and Ammunition Forum

Never the less, a braver man than I.

I very much doubt this the above was the cause , I think what we have here is maybe a mistake regarding the original story, I,m thinking it may of been commercial ammo first then the handloads, I would think he went over the required charge, this could or may have give the stated affects.... and maybe the wet feeling in ones pants.

Regarding my own downloads, the proof is in the pudding they say, click on the link below have a look at the target in the pic,

L42 repro at the range

[303Guy]

On this reduced load thing - many people use pistol and shotgun powders for cast bullet loads because they burn well at low pressures and it's much cheaper. Looking down into the mouth of a rifle case, the difference in hight between 13gr and 26gr of Red dot is negligible. But 26gr (a double load) is over the top.
I always advice against fast powders, suggesting a medium to slow powder that will not be an overload even with a full case. That too can be risky if too little of a too slow powder is loaded (S.E.E.) Pressures will then be low enough and velocity not too high (accuracy goes south with cast if pressure and velocity is too high). There is another powder that can be used in a rifle case for subsonic velocities with about the same burn speed as Red dot and that is Trail Boss. It's bulky stuff and fills the case! Unfortunately it is too fast so is useful only for light loads.