Interesting. I had my barrel off my S400 Classic last week as a strip down and rebuild/replace seals exercise as it wasn't holding air. I had no O rings on the brass section of the barrel at all. I haven't charged the rifle yet since putting it all back together.
What's the best way to check of any leaks around the barrel/breach area?
It's a concern that in this day and age a manufacturer of air rifles struggles machining something simple like male and female fitting joint to any consistent tolerances.
s400f barrel leak update
Re: s400f barrel leak update
Beaconjon wrote:Interesting. I had my barrel off my S400 Classic last week as a strip down and rebuild/replace seals exercise as it wasn't holding air. I had no O rings on the brass section of the barrel at all. I haven't charged the rifle yet since putting it all back together.
What's the best way to check of any leaks around the barrel/breach area?
It's a concern that in this day and age a manufacturer of air rifles struggles machining something simple like male and female fitting joint to any consistent tolerances.
i notice the leak when gun oil that had seeped into the joint was spitting out after each shot and ending up on the bottom of the scope. so put some gun oil down there and look for oil spitting out .
Russ
Re: s400f barrel leak update
retroruss wrote:Beaconjon wrote:Interesting. I had my barrel off my S400 Classic last week as a strip down and rebuild/replace seals exercise as it wasn't holding air. I had no O rings on the brass section of the barrel at all. I haven't charged the rifle yet since putting it all back together.
What's the best way to check of any leaks around the barrel/breach area?
It's a concern that in this day and age a manufacturer of air rifles struggles machining something simple like male and female fitting joint to any consistent tolerances.
i notice the leak when gun oil that had seeped into the joint was spitting out after each shot and ending up on the bottom of the scope. so put some gun oil down there and look for oil spitting out .
Russ
A small piece of tissue paper perched on the barrel and/or the breech makes a lot less mess

Alan
Re: s400f barrel leak update
Maybe a cure to this problem would be when fitting the barrel make sure the two top mounting grub screws are done up tight before tightening the one underneath, thus making a good seal, similar to the Rapid 7.
Jez.
Jez.
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Re: s400f barrel leak update
Making the barrel the right size would be better as would designing in O rings either side of the xfer port as standard rather than bodging only sloppy ones, which in any case should have been reworked or scrapped at source. We are talking £500 - £800 rifles. I'm a big fan of the AA concept but the occasional bad one will spoil the legacy.
Re: s400f barrel leak update
TenMetrePeter wrote:Making the barrel the right size would be better as would designing in O rings either side of the xfer port as standard rather than bodging only sloppy ones, which in any case should have been reworked or scrapped at source. We are talking £500 - £800 rifles. I'm a big fan of the AA concept but the occasional bad one will spoil the legacy.
That is so true peter, spoiling the ship for a lickle bit of tar. Rog
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Re: s400f barrel leak update
Jezzer wrote:Maybe a cure to this problem would be when fitting the barrel make sure the two top mounting grub screws are done up tight before tightening the one underneath, thus making a good seal........
Jez.
That's exactly what I had to do to cure mine. It was leaking from between the top of the probe and the breech seal and replacing the breech seal a number of times made no difference. I finally figured that the problem was that the breech seal was not properly aligned with the probe - tightening down the top two mounting grub screws thereby moving the breech seal down in relation to the probe finally sorted it.
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Re: s400f barrel leak update
ok so i finally fixed this barrel/breech block leak. i found when fitting the new barrel seals the grub screw and transfer port holes would nick a small piece of the seals off
as i carefully put the barrel in the breech block and also when taking the barrel out and again the new seals were cut just like the originals when i took the barrel out.
after realising what was happening i found pieces of the original seals as well as the new seals in the grub screw holes. i got some 8mm dowel and used 800 wet n dry paper
to carefully remove the sharp burrs from the holes so the seals could pass without damage . i found looking down the holes with a light as the seals passed and rotating the barrel slightly helped them pass
the holes easier not getting trapped.
i used 2 s650a 8 x 1mm seals and coat of Wellseal around the barrel between the seals and this so far has fixed the leak .
Russ
as i carefully put the barrel in the breech block and also when taking the barrel out and again the new seals were cut just like the originals when i took the barrel out.
after realising what was happening i found pieces of the original seals as well as the new seals in the grub screw holes. i got some 8mm dowel and used 800 wet n dry paper
to carefully remove the sharp burrs from the holes so the seals could pass without damage . i found looking down the holes with a light as the seals passed and rotating the barrel slightly helped them pass
the holes easier not getting trapped.
i used 2 s650a 8 x 1mm seals and coat of Wellseal around the barrel between the seals and this so far has fixed the leak .
Russ
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