TargetTalk

Can anybody supply/advise the correct cylinder filling procedure (CO2) for the FWB model 2 air pistol.

Nothing to it.

Put the cylinder in the freezer for a couple of minutes then attach to the bulk tank. Keep in mind that you are handling a liquid, not a gas. If the tank does not have a siphon you must invert it. Open the valve for a few seconds, close it, unscrew cylinder.

Your gun may have to be cocked when putting the cylinder on.

Another hint in addition to Rovers, is to sit the CO2 cylinder in the kitchen sink, with about 5 inches of hot water for about 5 minutes, before filling, or alternatively, if the weather is warm, sit it in the sun for 10-15 mins. ... this will further enhance the amount od CO2 entering your AP cylinder.

Sorry, Deadeye, but the opposite is true (but perhaps you mean the large tank). The cylinder should (not must) be chilled before filling.

I have found that if you get the cylinder REALLY cold, you can fill it so much that the gun won't work without bleeding it down a little.

Some suggest using a scale to get the proper weight of CO2 in the cylinder, but I find that a PIA.

If you know you're running low on CO2 and don't have a handy freezer or the time to let the shooting cylinder chill, take it off the gun before it's exhausted and bleed off some CO2 using the gas bleed attachment that came with the gun.

This will reduce the temperature of the cylinder enough to give you a good fill. In extremis (you ran completely out of gas and don't have enough to bleed), fill the thing directly from your bulk CO2 cylinder and accept that you're only getting about half the amount of gas that you would with a good refrigeration cycle.

I agree with the person who suggested chilling the cylinder. Chill it or bleed what you can get into it (rapidly escaping gas will cool the cylinder...) to chill the cylinder.

Here are two important details to remember.

First, check the weight of the cylinder empty, fill it to the spec on the cylinder and not more. I believe the empty weight should be labeled as tare or something like that. There will be a full weight, too, immediately after that weight.

Overfilling will cause weak discharges when the cylinder is at room temperature until you get some of the CO2 out.

Second, fill several hours before you shoot and let the cylinders rest at room temperature. Shooting with cold cylinders could cause fluctuation in velocity and, therefore, zero of the gun.

Good luck,
Retired

[

quote]Rover



Joined: 15 Nov 2008
Posts: 387
Location: Scottsdale AZ
Posted: Sun Mar 28, 2010 6:42 am Post subject:

--------------------------------------------------------------------------------

Sorry, Deadeye, but the opposite is true (but perhaps you mean the large tank). The cylinder should (not must) be chilled before filling.

I have found that if you get the cylinder REALLY cold, you can fill it so much that the gun won't work without bleeding it down a little.

Some suggest using a scale to get the proper weight of CO2 in the cylinder, but I find that a PIA.

No need to be sorry Rover, as I definately mean the LARGE [supply] cylinder. I couldn't imagine heating the AP cylinder.
By heating the main source of CO2, and cooling the recipient cylinder [AP cylinder] you double the advantage of just cooling the AP cylinder only.
Not rocket science, and when you try it you will see the added benefit.

Deadeye,

Absolutely correct. That's why I qualified my response. The cylinder needs to be around 20F cooler than the supply.

I can't imagine that it's easier to heat a 20 pound tank than to cool a few ounce cylinder, but I can see some circumstances where it might be necessary.

Here in hot desert Arizona I have trouble with overfilling the cylinders rather than squeezing in the last bit.

It is definately not easier to heat the 20 odd pound supply cylinder, but in less agreeable winter climates than Arizona, it is a huge benefit to chill one [AP], and warm the other[supply] to raise the differential. Normal house temperature of 70-75degrees F is not sufficient, and placing the supply cylinder in a sink or like container with hot water, even though its a pain, works very well indeed.
During the warmer months, we would place the supply cylinder out in the sun for 5 mins. or so, to acheive the same added benefit.

When I owned a FWB model 2, I always bled off some of the remaining CO2 in the cylinder to chill it. I then filled from the supply tank and finally weighed the cylinder with a postal scale and bled off any excess CO2. The FWB model 2 is a fine gun.