Advice needed ... bolt opens on firing!

[Peter Laidler]

The right hand side LONG locking shoulder MUST bear hard against the locking shoulder of the body when the bolt is closed and locked down, as must the left side locking shoulder. AND the bolt handle MUST touch the butt socket when the rifle is loaded and locked.

You're not being ridiculous - quite yet...... Your rifle needs to be looked at PDQ by someone who knows what he's doing as it seems as though we're all pxxxxxg into the wind here if I might be so diplomatic as to offer that opinion. Others might agree or disagree

[Son]

Thank you Thunderbox. I couldn't remember specifics about the cases I'd heard about but your post has jogged my memory. Yes, they had aftermarket springs fitted! The springs were not finished smoothly on the ends, leaving a sharp step which created the grip.

Just to add to what Peter is saying, here's a pic showing the cam lug on top of the cocking piece. If this is missing, opening the bolt will not be engaging the cam lug which would make bolt lift very easy. It will also be causing a dangerous situation where the striker can be present through the bolt face while cycling the action until the cocking piece engages the sear. This is because the lug would normally be holding the cocking piece and striker back a little in the short cam groove once the handle is lifted.

Attachment 45849

[spentprimer]

The right hand side LONG locking shoulder MUST bear hard against the locking shoulder of the body when the bolt is closed and locked down, as must the left side locking shoulder. AND the bolt handle MUST touch the butt socket when the rifle is loaded and locked.

Both locking shoulders bear against the receiver body. The way the wear marks are I would estimate 50% to 60% contact area on each shoulder and they appear equally marked.

---------- Post added at 05:34 PM ---------- Previous post was at 05:27 PM ----------

Thank you Thunderbox. I couldn't remember specifics about the cases I'd heard about but your post has jogged my memory. Yes, they had aftermarket springs fitted! The springs were not finished smoothly on the ends, leaving a sharp step which created the grip.

Just to add to what Peter is saying, here's a pic showing the cam lug on top of the cocking piece. If this is missing, opening the bolt will not be engaging the cam lug which would make bolt lift very easy. It will also be causing a dangerous situation where the striker can be present through the bolt face while cycling the action until the cocking piece engages the sear. This is because the lug would normally be holding the cocking piece and striker back a little in the short cam groove once the handle is lifted.

Attachment 45849

Thanks for the great photo and accompanying nomenclature. They say it is all the King's English, but, I am amazed at the differences. It wasn't until I bought a '69 B Series Roadster from Morris Garages that I learned my automobile had a boot & a bonnet! And I think they put the steering wheel on a different side than the one Peter probably has.

[5thBatt]

I'll just throw this out there, what about the cocking piece slamming into the rear of the bolt body? this i would thing could cause the bolt to lift, check the gap between the cocking piece & the bolt body with the bolt closed & uncocked, there should be a gap.

[spentprimer]

I'll just throw this out there, what about the cocking piece slamming into the rear of the bolt body? this i would thing could cause the bolt to lift, check the gap between the cocking piece & the bolt body with the bolt closed & uncocked, there should be a gap.

http://imageshack.us/a/img547/1472/1zwq.jpg

I just checked it and it does not touch, it is close, but I can see maybe .025" of light between them.

Just curious, could a weak fring pin spring cause this to happen? I ask because I have an old Mauser that I had un-cocked with the bolt out. It took a great amount of force to get that to move up the ramp to being cocked again. When I do this with the Enfield I find it moves quite easily. Granted, they are two different designs and all, but, the Mauser takes several orders of magnitude more effort to cock with the bolt out of the action than the Enfield does.

[spentprimer]

Anyway..... to test Sons theory you could just unscrew/remove the bolthead, press the striker IN against a block of hard wood, hold the cocking piece and rotate the bolt 90 degrees right as if to close. If it winds back on itself, you've got the answer. But if it don't..................

And another thing to remember is this. While your bolt is mysteriously unlocking itself, it has got to do it with some degree of difficulty because the safety stud on the cocking piece has now still got to lever itself from the long can groove in the bolt to the short cam groove. And that takes quite a bit of effort as you can see/feel when you do it by hand.

Just my 2c's worth. But I'll

Peter, I did your described test and it did not unwind, it stayed stationary. However, the cocking piece moves much easier than a Mauser cocking piece when moving from un-cocked to cocked. Could a weak firing pin spring/mainspring cause this to rotate when fired? I am guessing it could if the little ramp is all that is keeping the bolt handle locked down.

[Peter Laidler]

Phew............ We've had sooooooooo many variations on this saga that I am totally lost. First opening on firing appears to have happened once then it's all the time then the locking shoulders don't engage the locking cams - then they do and........... I'm out of here. It's getting bigger than Ben-Hur out there! Maybe the more experienced can help

[browningautorifle]

Maybe the more experienced can help

Pretty funny...!

[muffett.2008]

Is it only me? or has anyone else noticed Peter is becoming more cranky and cynical now he's retired?

[303Guy]

I am really interested in this problem and do hope someone can come up with and answer.

I do have a related question; the bolt kick-up that some rifles have, is that caused by the bolt handle resting on the action body (which I accept must contact - there's nowhere else to stop the bolt rotation)? Why do some lift and not others? Or am I just not noticing it so much? My uncle who was an armourer in Africa told me about it and said not to worry about it. He said some don't like it and that was all he said.