Store with cylinder on or off?

[Agt. Smith]

Searched around and couldn't find anything here.

Better to store (days, not weeks or months) with the PCP cylinder on or off? (as long as the filling probe stays clean of course)

[David M]

I prefer cylinder "Off" as it reduces pressure on the springs of the reduction valve.
Some mfg. supply a spacer to fit between the tank and frame that disconnects the fill valve
to do the same job i.e drop the pressure on the valve.
Just as easy to unscrew the tank completely, do not just partly unscrew and leave on the gun
as loose fitting tank may rattle, damaging the threads.
Use the spacer or take the tank off.

[Agt. Smith]

Intuitively, this is what I've been doing. It makes sense that this would stress the mechanism/seals less.

Also - I've been using a very little grease (Anschutz 4425) on the center section of the probe like every 10 cylinders. More? too much?

Thanks for the response.

[Gwhite]

Pilkington recommends leaving it off, but at least one manufacturer (Feinwerkbau?) suggests leaving it on.

If you are shooting regularly, I would leave it on. Taking it on & off every day will just wear out the O-rings & threads prematurely. Keeping the cylinder interface closed also keeps any dust/dirt out.

For storage periods greater than 1 week, I think "best practice" would be to unscrew it just enough to vent the pressure. I never bother, except for very long storage (like over the summer for the college team I help coach).

The cylinder interface will typically vent when unscrewed more than where the valve opens when you screw it on. Once I've dumped the pressure, I screw the cylinder back on until I feel the valve pin just make contact. I then back off an eight of a turn. That leaves the threads engaged enough to keep everything supported so the threads are unlikely to get damaged. A spacer would be even better, but I've never bothered.

O-rings like to be greased, as do aluminum on aluminum threads. HOWEVER, only a thin film is required. Gooping things up just wastes grease and attracts dirt, which O-rings do NOT like. Brass on aluminum threads (like on Steyrs) aren't at risk of galling.

There was a lengthy discussion about grease in another topic, but the stuff I like & Pilkington recommends for both O-rings & cylinder threads is Super Lube Synthetic Grease in the 1/2 oz tube (#21010).

[B Lafferty]

I unscrew the cylinder and leave it on. It might rattle and damage threads in some storage cases. However, the Hammerli case for the AP-20 holds everything in a good foam sandwich. I do place the 2"x1" vinyl markers that I cut out from a roll up chess board between the cylinder and the compensator as a precaution to minimize any movement in the foam sandwich. I use the markers to set out where my feet are placed when shooting so that I can step away and return to shooting without finding my foot position anew.

[Agt. Smith]

I unscrew the cylinder and leave it on. It might rattle and damage threads in some storage cases. However, the Hammerli case for the AP-20 holds everything in a good foam sandwich. I do place the 2"x1" vinyl markers that I cut out from a roll up chess board between the cylinder and the compensator as a precaution to minimize any movement in the foam sandwich. I use the markers to set out where my feet are placed when shooting so that I can step away and return to shooting without finding my foot position anew.

I think the K12 case would offer the same kind of protection. But, when I do shoot - it's usually 60-120 shots anyway, so it feels easier to just remove it because I know I need to fill it anyway.

By the way, I changed my first filter in the Vevor after ~20 K12 cylinders (they recommend 50!). WOW - talk about a crappy dirty filter. I fill it only in a relatively clean portion of the basement where I reload, but holy crap that thing was dirty. Dark brown, especially on the inlet end.

[B Lafferty]

I unscrew the cylinder and leave it on. It might rattle and damage threads in some storage cases. However, the Hammerli case for the AP-20 holds everything in a good foam sandwich. I do place the 2"x1" vinyl markers that I cut out from a roll up chess board between the cylinder and the compensator as a precaution to minimize any movement in the foam sandwich. I use the markers to set out where my feet are placed when shooting so that I can step away and return to shooting without finding my foot position anew.

I think the K12 case would offer the same kind of protection. But, when I do shoot - it's usually 60-120 shots anyway, so it feels easier to just remove it because I know I need to fill it anyway.

By the way, I changed my first filter in the Vevor after ~20 K12 cylinders (they recommend 50!). WOW - talk about a crappy dirty filter. I fill it only in a relatively clean portion of the basement where I reload, but holy crap that thing was dirty. Dark brown, especially on the inlet end.

You can also just make an additional insert with some foam. An old couch cushion, perhaps.

[Gwhite]

I unscrew the cylinder and leave it on. It might rattle and damage threads in some storage cases. However, the Hammerli case for the AP-20 holds everything in a good foam sandwich. I do place the 2"x1" vinyl markers that I cut out from a roll up chess board between the cylinder and the compensator as a precaution to minimize any movement in the foam sandwich. I use the markers to set out where my feet are placed when shooting so that I can step away and return to shooting without finding my foot position anew.

If you think you can shoot an entire match without your muscles tiring & stretching (which will change your natural point of aim), you are probably kidding yourself.

I always enjoy competing next to people who do the tape, chalk, etc. thing with their foot position. I know by the end of the match, their natural point of aim will be off...

How often you should check depends on your physical condition, and how much you stretch before you shoot.

[stephen_maly]

I encountered what seemed to be a very strange situation. I left the cylinder attached fully to my old Steyr LP10. I only removed the cylinder to recharge it. While the air cylinder is in place, the release(?) / firing valve (which allows air to proceed to push the pellet out) is forced shut. After enough time in the Austin, TX area, when I removed the air cylinder, I found that regulator would retain air, and fire acouple of times before it was empty. I also found that firing the pistol resulted in erratic air charges, hence varying velocities. I dissassembled the regulator and cleaned off the valve. There was no visible build-up of any material, but after I carefully cleaned off the valve, the gun fired properly. I could only surmise that keeping the valve shut under 50 atm's of pressure, some residual chemicals in the air, stuck to the surface, and helped to "glue" it. After that, I removed the cylinder between practices, and I had no further problems. If it were I, I would remove the cylinder between practices or for longer storage.

[B Lafferty]

I unscrew the cylinder and leave it on. It might rattle and damage threads in some storage cases. However, the Hammerli case for the AP-20 holds everything in a good foam sandwich. I do place the 2"x1" vinyl markers that I cut out from a roll up chess board between the cylinder and the compensator as a precaution to minimize any movement in the foam sandwich. I use the markers to set out where my feet are placed when shooting so that I can step away and return to shooting without finding my foot position anew.

If you think you can shoot an entire match without your muscles tiring & stretching (which will change your natural point of aim), you are probably kidding yourself.

I always enjoy competing next to people who do the tape, chalk, etc. thing with their foot position. I know by the end of the match, their natural point of aim will be off...

How often you should check depends on your physical condition, and how much you stretch before you shoot.

Agreed. I use it as a point of reference. With the sciatica that I'm constantly dealing with, it helps to take a break and stretch. When I come back to the line, the shooting position usually needs adjusting. The marker for my left toe usually remains in place with the right foot often adjusted slightly. More often than not, the orientation of my feet, toe in/toe out, will change more than the placement of the foot otherwise. I will usually shoot the first twenty shots without changing anything. After that, I stretch after every ten shots. As Bette Davis said, "Growing old isn't for sissies."