Should PCP Airguns leak a little?

[ftsefund]

Say I filled my air rifle to 200 bar. If I leave it alone and come back next week should it still read 200. If I leave it for a month, 3 months, 1 year should it still read 200? What is considered acceptable leakage? No leakage, 1 bar a week? I know if I filled up my car tyres to say 35psi, a month later it wouldn't be 35psi.

[angrybear]

No they should not leak

Neither should your tyres,
but they will be effected by temperature ie if you fill them at a garage while hot from driving when they cool the pressure will drop, also the weight of the vehicle (loaded/unloaded) exerts physical load on to a tyre allowing/preventing expansion of the rubber.

[Phil Russell]

I have heard some people say they are happy with a very slow leak / seepage of air as it does not matter to them if they are using the gun regularly and hence refiling regularly.
But it would concern me. I have a Huntsman MK2 that was filled and left over a year ... no change. My S400 is used infrequently for pest control (usually the odd rat) and I guess I refill every year, allowing for some fun zeroing shots on the way. No leaks. So, my view is that they should not leak.
Cheers, Phil

[gingernut]

As my plumber says there is no such thing as an acceptable leak.
But as Bear says temperature induced variations are to be expected.
As ever regular use is a good idea.

[Two200's]

Mmmmm.
There are very few things actually air tight.

I would expect a bit of pressure loss, nowt dramatic, but some.

[shauny]

leaks not good,as you never hear of a leak getting better,only worse.

[sevorg]

Should not leak at all. My HW100 didn't get used for over six months and my son's S410 has been in the cupboard for nearly three years and the pressures remain unchanged.

I guess if you have a very slow leak you might choose to live with it and if you shoot frequently you may never notice you have one.

[SpitFirefox]

No they should not leak

Neither should your tyres,
but they will be effected by temperature ie if you fill them at a garage while hot from driving when they cool the pressure will drop, also the weight of the vehicle (loaded/unloaded) exerts physical load on to a tyre allowing/preventing expansion of the rubber.

Tyres leak - other than through a faulty valve or cracked wheel, there's a large mating surface between the tyre and wheel which leaks when the wheel coating starts to corrode...but the oxygen molecules in air slowly permeate through the tyre rubber. The valves at the fill end and outlet end of an air rifle are the only component in common with a car tyre and if they are leaking there's something wrong with them.