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Help with bulk fill

Lobi

Member
Feb 11, 2023
172
142
Michigan
My new (old) Crosman Trapmaster came today. The tube that originally would have held the 12g powerlets has a bulk fill adapter. I assume with the internal threads showing that a "bulk fill" is performed by screwing on a tank. How do I know when the onboard tank is full? I have several pcp guns and they all have a visual gauge.
Is bulk fill always CO2? Does it have to be? Will it be possible to fill with compressed air from my large pcp fill tank? I'll be buying one or more small tanks to have filled with co2? Have to go to paintball place for this?

Sorry so many noob questions. Brand new method to me. Thanks in advance for any explanations.

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When you bulk fill, you need the fill tank inverted so the liquid CO2 will flow into the rifle reservoir. It will stop flowing when full... you can hear it. From what I can see, the seal is gone on the fill port... won't work without that. It will audibly change when shooting and the velocity will go down when the liquid runs out... it's what keeps the pressure constant . No good way to know how much remains in the rifle.

You can use air but keep in mind that CO2 devices are designed around a max pressure of 2k psi and typical working pressures are in the neighborhood of 800 psi. CO2 has a pretty steep pressure vs temp curve so changes in temp yield significant changes in pressure. Depending on the quality of the rifle or pistol , I would stay at 1000 psi and below and you won't get many shots compared to CO2 but air CAN be used... just stay on the safe side.

I get my 30 lb welding tanking filled for about $22 and it will fill my small tanks a LOT of times. You will need an adapter to go from the welding tank to the small tanks and will need to keep in mind the liquid flow thing. Mac1 used to sell all kinds of CO2 accessories and adapters but you would need to contact them to know.

Bob
 
When you bulk fill, you need the fill tank inverted so the liquid CO2 will flow into the rifle reservoir. It will stop flowing when full... you can hear it. From what I can see, the seal is gone on the fill port... won't work without that. It will audibly change when shooting and the velocity will go down when the liquid runs out... it's what keeps the pressure constant . No good way to know how much remains in the rifle.

You can use air but keep in mind that CO2 devices are designed around a max pressure of 2k psi and typical working pressures are in the neighborhood of 800 psi. CO2 has a pretty steep pressure vs temp curve so changes in temp yield significant changes in pressure. Depending on the quality of the rifle or pistol , I would stay at 1000 psi and below and you won't get many shots compared to CO2 but air CAN be used... just stay on the safe side.

I get my 30 lb welding tanking filled for about $22 and it will fill my small tanks a LOT of times. You will need an adapter to go from the welding tank to the small tanks and will need to keep in mind the liquid flow thing. Mac1 used to sell all kinds of CO2 accessories and adapters but you would need to contact them to know.

Bob
Thank you sir. This is the kind of answer I was looking for. I literally knew nothing about co2 bulk filing. Not sure I'm going to buy a bulk co2 tank and little refill tanks. I'm spread thin with every other kind of air gun and fill type. Might try and rig up a way to put 1k psi in from my big pcp air tank just to attempt shooting her. Looking around for the original piercing cap for this gun so I could just use her with the co2 cartridges.
Thanks again
Dave
 
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