Cocking bolt movement

Cocking bolt movement

Postby dazzler » Mon Aug 28, 2017 8:38 am

Hi everyone

The cocking bolt on my s400 "bounces" on firing. Fires ok and there doesn't seem to be any leaks but the bolt is very loose, the gun is old and the whole pellet probe feels very loose. Is there a quick, easy and cheap fix for this?

Thanks everyone

Bobby
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Re: Cocking bolt movement

Postby TenMetrePeter » Mon Aug 28, 2017 9:04 am

There should be an o ring between the bolt head and the housing to give cushion and friction. You could replace it but not sure if it can be stretched over the bolt handle. If not the bolt handle may need some heat to soften the Loctite to remove it.
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Re: Cocking bolt movement

Postby Roger5 » Mon Aug 28, 2017 12:11 pm

TenMetrePeter wrote:There should be an o ring between the bolt head and the housing to give cushion and friction. You could replace it but not sure if it can be stretched over the bolt handle. If not the bolt handle may need some heat to soften the Loctite to remove it.

You can stretch ot over the bolt handle, no problem. Rog ;)
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Re: Cocking bolt movement

Postby dazzler » Mon Aug 28, 2017 1:30 pm

Ok thanks for your help so far with this. Ordered a seal set, so I will change this one first and see how we go.

Cheers & ATB

Bobby
Pain or damage don't end the world. Or despair or f...... beatings. The world ends when you're dead. Until then, you got more punishment in store. Stand it like a man, and give some back.

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Re: Cocking bolt movement

Postby dazzler » Fri Sep 01, 2017 5:12 pm

Eh up everyone.

Seal kit arrived and swapped out the seal that sits just on the inner edge of the bolt, and it hasn't helped at all. There seems to be a little gap between the action and the bolt when it's closed, even with the slightly larger section seal on there. Just noticed the bolt end (the ball end) actually touches the stock when in the closed position.

Is there anything else I can do?

Thanks for ya help everyone.

Bobby
Pain or damage don't end the world. Or despair or f...... beatings. The world ends when you're dead. Until then, you got more punishment in store. Stand it like a man, and give some back.

Albert Swearengen
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Circa 1878
dazzler
 
Posts: 56
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Location: Burnley NWUK

Re: Cocking bolt movement

Postby TenMetrePeter » Fri Sep 01, 2017 5:23 pm

It should go within say 5mm of the stock but not touch any wood. My mates brand new MPR had that problem and the bolt would blow out on shooting.
Undo the allen screw in the handle and see if the handle will easily reposition and tighten up. If its easy to move then really some loctite in there would help it stay in position in the long term. I would remove the handle and make sure there's no debris of old loctite in there - the handle may not even be fully tightened down.

Two points.

Dont use green "bearing fit" if you think it will need a total dismantle later. Use a weaker loctite. Keep it off the thread, just a drop inside the handle.
Secondly dont let loctite get into the gun body or the bolt will be stuck. Be very clean and use grease on the bolt where it goes into the gun.
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Re: Cocking bolt movement

Postby dazzler » Fri Sep 01, 2017 7:26 pm

Thanks Peter,

The bolt only just touches woodwork. I have removed the allen bolt holding the bolt on but cant actually pull the bolt off - it's very tightly stuck on there. May use a hair dryer to soften up any Loctite that may have been used on assembly.

On firing there is just a bounce of the bolt as it doesn't `lock` down into the firing position. There is no blowback of the bolt and probe.

Thanks again for your help, I will get the bloody handle off if it kills me. :lol: Then hopefully it will be just the case of finding out how to keep the bolt locked down. My BSA and Daystate bolts stay down where they should.

Regards

Bobby
Pain or damage don't end the world. Or despair or f...... beatings. The world ends when you're dead. Until then, you got more punishment in store. Stand it like a man, and give some back.

Albert Swearengen
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Circa 1878
dazzler
 
Posts: 56
Joined: Thu Jul 14, 2016 1:57 pm
Location: Burnley NWUK

Re: Cocking bolt movement

Postby TenMetrePeter » Fri Sep 01, 2017 10:02 pm

It's just friction between peg and slot inside the mechanism caused by the o ring compression. The peg or slot could be worn and thats a big strip down.

If necessary wrap a wet cloth round the cocked bolt and use a little butane pencil torch or cook's brulee torch on the handle.
Fatter o ring is obviously one way to go but you need to make sure there is a definite gap between handle and stock. Careless handling in a rifle case can close the gap.
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