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viper2788 · Member

I've had a benjamin disco for awhile now and I've always kept it at around 1000psi before storing it away. Should I keep it higher or lower... and does it really matter? My friend with a 392 always leaves one pump so I was wondering about mine.

AirGunEric · Site Admin

I don't think it really matters- a little bit of air pressure probably won't hurt anything- but I don't know that pressurized or totally empty really makes a difference. I am unaware of anyone storing 2 identical rifles in a closet for 10 years, taking out and then comparing the seals for the point of a research project.

radar · Silver Status Member

I don't know for sure if it matters, but I store at 1/2 pressure for long term so 1000 psi would be about right.

The reason I've done this is a lot of people say it's better to keep the seals under pressure...so maybe it is and, maybe it isn't, but it can't hurt I guess. So that's why I store under pressure if the gun holds air. The reason I do not store under full pressure, is for concerns of moisture. When air pressure goes up, moisture in the air condenses into liquid. I figure that if the pressure was at 2000 psi, for example, all the moisture that will condense at that pressure will do so. When it is shot down to 1000 psi, the rest of the moisture has a chance to evaporate back into the air inside, rather than having a small puddle of water sloshing around inside the steel tube.

That's my theory, and I'm going with that. Never had a PCP problem doing it this way.

I also store pump-up guns with 1 pump of air except for the Daisys I have that would have to be left cocked to keep air inside. Those are stored empty, and I've never had a problem with those, either.

Slavia · Moderator

I've read an equal amount going both ways - stored with pressure, or not. The only explanation that has made sense to me is that it depends on the valve design. If the valve is held open on discharge, then dust can infiltrate over long storage periods. If it closes itself, then there is no need.

For example, the valve on my 2240 closes without pressure, so I store it that way. My Sheridan's valve stays open - without cocking it you can pump all day and listen to the air coming out of the muzzle. I cock it, put one pump in, and then de-cock it by pulling the trigger and easing the bolt forward. My 2004 (P-17) pistol has a valve that says open, but there is no way to de-cock it, so I leave it uncharged.

I think in the end Eric is right - it's all opinion with only anecdotal data to support it. On the other hand, storing under pressure will apparently cause no harm, so do what makes sense to you.

On another tangent: If you're into airguns enough so that the pressure question matters, how are you going to stand leaving one of your beautiful toys in a closet for 10 years?

viper2788 · Member

Robw · Veteran Member

PCPs should be kept at least at the lowest usable pressure. (the pressure
that you would shoot down to before a refill). This keeps the seals
conformed to their seats. They can be stored indefinitely at full pressure
with NO ill affects. I store all of my PCPs at full pressure, ready to shoot.

It does not make ANY difference with pumpers or single strokes.