I realise I am in a niche market owning the S400 MPR precision rifle with removable cylinder but general advice is sought from members.
I refill every week just before competition so the cylinder gets unscrewed every week anyhow and so any argument about wear on threads is not so relevant.
The question is, given the alleged tendency for AA firing valve heads to extrude over time, is is better to have the cylinder out of the gun during the week and replaced just before use or leave it in all week and just remove for refill?
For the sake of argument assume the cylinder seal is sound.
Advice on removable cylinder
- TenMetrePeter
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- Joined: Wed Jun 29, 2016 5:40 pm
- Location: Luton Beds UK
Re: Advice on removable cylinder
Hi Peter, your mpr precision and the S400 series don't have much in common with the firing valve setups, and the extrusion problem, is as far as I'm aware only relevant to the standard 12ftlb S400/410/510 rifles and easily sorted with a new firing valve if its become a problem. RogTenMetrePeter wrote: ↑Thu Jul 05, 2018 9:50 amI realise I am in a niche market owning the S400 MPR precision rifle with removable cylinder but general advice is sought from members.
I refill every week just before competition so the cylinder gets unscrewed every week anyhow and so any argument about wear on threads is not so relevant.
The question is, given the alleged tendency for AA firing valve heads to extrude over time, is is better to have the cylinder out of the gun during the week and replaced just before use or leave it in all week and just remove for refill?
For the sake of argument assume the cylinder seal is sound.
- TenMetrePeter
- Posts: 1043
- Joined: Wed Jun 29, 2016 5:40 pm
- Location: Luton Beds UK
Re: Advice on removable cylinder
The other problem is there's no stripdown info online. No idea how the parts disassemble and I wouldnt want to be the first person to put a pipe wrench on the cylinder extension!
Air Arms just wrote to me and said leaving the cylinder off or leaving it on are both just fine Also remove and top up any time is fine too.
EDIT: I just rechecked. They share the same firing valve S370.
If it ever plays up I think I will reluctantly try a service depot. All my playing about has been with the stocks and the action is totally untampered with.
Air Arms just wrote to me and said leaving the cylinder off or leaving it on are both just fine Also remove and top up any time is fine too.
EDIT: I just rechecked. They share the same firing valve S370.
If it ever plays up I think I will reluctantly try a service depot. All my playing about has been with the stocks and the action is totally untampered with.
Re: Advice on removable cylinder
Hi Peter, just had a look on the Rothery site, and they look pretty simple to me, I originally thought they were like the S200 screw on cylinder set up, but they aren't, so yes, I suppose the extrusion problem could apply to them also, if you do take it apart, measure the pot, so it goes back the same length. RogTenMetrePeter wrote: ↑Thu Jul 05, 2018 7:56 pmThe other problem is there's no stripdown info online. No idea how the parts disassemble and I wouldnt want to be the first person to put a pipe wrench on the cylinder extension!
Air Arms just wrote to me and said leaving the cylinder off or leaving it on are both just fine Also remove and top up any time is fine too.
EDIT: I just rechecked. They share the same firing valve S370.
If it ever plays up I think I will reluctantly try a service depot. All my playing about has been with the stocks and the action is totally untampered with.
- TenMetrePeter
- Posts: 1043
- Joined: Wed Jun 29, 2016 5:40 pm
- Location: Luton Beds UK
Re: Advice on removable cylinder
It doesnt seem to have a pot, just a spring retainer that looks from the diagram rather like the bottom part of a normal pot.
If the valve is the same and both use 180 Bar I'm guessing the valve will age the same way.
I tend to use the Rothery diagrams for reference then order from Julian
If the valve is the same and both use 180 Bar I'm guessing the valve will age the same way.
I tend to use the Rothery diagrams for reference then order from Julian

Re: Advice on removable cylinder
Sorry Peter, when I said pot, I should probably have said spring retainer, but in reality it's the same thing, just measure it so it can be returned to original setting. RogTenMetrePeter wrote: ↑Sat Jul 07, 2018 5:31 pmIt doesnt seem to have a pot, just a spring retainer that looks from the diagram rather like the bottom part of a normal pot.
If the valve is the same and both use 180 Bar I'm guessing the valve will age the same way.
I tend to use the Rothery diagrams for reference then order from Julian![]()
- TenMetrePeter
- Posts: 1043
- Joined: Wed Jun 29, 2016 5:40 pm
- Location: Luton Beds UK
Re: Advice on removable cylinder
Spot on.Roger5 wrote: ↑Sat Jul 07, 2018 7:19 pmSorry Peter, when I said pot, I should probably have said spring retainer, but in reality it's the same thing, just measure it so it can be returned to original setting. RogTenMetrePeter wrote: ↑Sat Jul 07, 2018 5:31 pmIt doesnt seem to have a pot, just a spring retainer that looks from the diagram rather like the bottom part of a normal pot.
If the valve is the same and both use 180 Bar I'm guessing the valve will age the same way.
I tend to use the Rothery diagrams for reference then order from Julian![]()
If I ever have the nerve to try and separate two beautifully anodised cylinder parts, thats what I'll do

Mean time my gun sits in the cabinet with a loose cylinder til Tuesday.
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