Charging Air Pistol Cylinders

As I am charging the cylinders for my LP50, the pressure in my 200 bar tank drops with each charge. And, as the pressure in the tank drops, so does the pressure in the cylinders, as I charge the. Thus, I cannot fully charge the cylinders. And with each charge, the cylinders are filled a little less.
Is this par for the course and I should just top off my tank, as the pressure drops? Or is there a gadget of sorts that would allow me to fully charge the cylinders, even as the pressure in the tank drops?

Thanks for the advice,
Oleg.

That is how it works. If you have one of the hand pumps and really want full cylinders, you can top them off that way. Alternatively you can get a compressor to fill the cylinders.

Don't worry about it. The gun regulates down to about #800 psi anyways so the only thing you gain is capacity of shots which, you don't really need. My scuba is at around 1600 and I can still get a full match with a fill there.

If you're running competitions then you might stage several tanks so only a little air is taken from the high pressure tank.

Same deal with CO2, l don't need a full cylinder. When I'm low, I bleed it and fill. I get a half fill and it's enough.

Thanks, folks!
The OCD part of me wants to have neatly filled-in cylinders. But I understand now that this is how it works.

Best Regards,
Oleg.

Oleg,

The only cure for your full to the 200 Bar line OCD is you have to get a Scuba tank that can be filled to over 3,000 PSI. I was lucky have been given a 3,500 PSI cylinder by my stepfather for my first fill tank. It gives me lots of fills to the 200 Bar line on my AP cylinders. Unless you can get a higher pressure cylinder on the cheap, you just have to be happy with how a 3,000 PSI Scuba tank winds down. The carbon fiber fill tanks that take either 4,000 or 4,500 (I can't remember which) fills are major $$$. 

You could try calling a local dive shop to see if they have any used high pressure steel cylinders for sale or give away. My local dive shop sometimes gets tanks in from divers retiring-they actually give the shop the tank-it's usually got an expired certification and they just want to get rid of it. My local dive shop gave me a nice  2,000 PSI 19 cu ft aluminum pony tank for free from such a situation, all I had to do was pay to dive shop get it recertified. I use the pony tank for fills when I am travelling to the range or a friend's house and I want to shoot more than 2 cylinders with the LP50-it will hold about 12 LP 50 compact cylinder fills.

Regards, 

Craig

Thanks, Craig. Now that I understand how this is supposed to work, I will just use my tank and will take it to the dive shop for recharging once it goes below 40% - 50%.

Best Regards,
Oleg.

Oleg, I don't use a PCP pistol, I have a LP-1 which uses CO2. Filling my cylinders is very different than yours. I use a 25 lb tank I rent from the welding shop (they certify there own tanks) there are 2 types of valves, I use the syphon type that fills my cylinder with liquid CO2 from the bottom of tank. We don't fill according to pressure but weight, so I use a digital kitchen scale and weigh the tank to get the proper amount of liquid.
  CO2 has some disadvantages as far as performance in cold weather, but who shoots 10 meter at a cold range. I like my LP-1 because it was cheaper to start out with and Pilkington still has kits for conversion to PCP.
  Oleg you have a really nice pistol and if I wanted to top the cylinder, I'd use a hand pump. 
 Stan

When I bought my Steyr PCP I went to a local dive shop to check on tanks and air. The shop mentioned they were very familiar with what I wanted a tank for as they service the local high school air rifle teams needs. Cool. I bought a competitively priced tank from them. Since Air Pistol really doesn't use much air I have had a few times when I have brought the tank in for refill (top-off) because we see a less than full on our cylinder gauges and for the shop they barely need anything to top off the tank compared to a diver bringing a cylinder way down. Since I bought from them, several times I have not been charged to check the cylinder pressure.

One thing to keep in mind when you bring a tank to "top off',  for many dive shops, that last 500 to 1000 pounds is what costs the most money.