As indicated via a prior AGN post, I purchased from Rapid Air Weapons foster fill adapters to replace the standard Air Arms fill adapters and installed them on my .177 and .22 Air Arms rifles. Upon installation, they fit and filled perfectly.
A few days later, I shot my .177 rifle and went to fill it afterwards only to discover that it wouldn't take air. I disassembled the rifle again and upon removal of the valve found that the valve piston/plunger was very tight in valve cylinder. I had to use a tiny punch to push it back out. The only thing I could think of was that the rifles were stored in my cool basement vault (very dry though) and the metalurgy must have changed due to the temperatures. At any rate, I wrote to RAW and asked them to send me a replacement, thinking the tolerances might not be so severe.
Yesterday, I installed the replacement, and today shot both rifles, and upon trying to fill each of the rifles, had the same issue. This time, the light popped on in my head, and instead of attempting to fill from my 2900 PSI/200 BAR regulated tanks, I hooked them up to my 4500 PSI/300 BAR tank and the valves popped open allowing the guns to fill.
Giving this reflection, my guess is that the springs on the RAW pistons are too stiff to allow the lighter pressure tanks to open the valves. I haven't decided whether to go back to the Air Arms adapters, trim the springs on the RAW adapters, or see if once the guns are shot sufficiently and the temps warm-up a bit if the problem goes away.
Having a large steel and an Air Venturi 80 CU IN carbon fiber tank, that both have 2900 PSI outputs, I don't really want to give them up over a valve issue.
I will figure out a solution eventually - I just offer this more as an FYI to others that may be considering such a conversion.
DZ
A few days later, I shot my .177 rifle and went to fill it afterwards only to discover that it wouldn't take air. I disassembled the rifle again and upon removal of the valve found that the valve piston/plunger was very tight in valve cylinder. I had to use a tiny punch to push it back out. The only thing I could think of was that the rifles were stored in my cool basement vault (very dry though) and the metalurgy must have changed due to the temperatures. At any rate, I wrote to RAW and asked them to send me a replacement, thinking the tolerances might not be so severe.
Yesterday, I installed the replacement, and today shot both rifles, and upon trying to fill each of the rifles, had the same issue. This time, the light popped on in my head, and instead of attempting to fill from my 2900 PSI/200 BAR regulated tanks, I hooked them up to my 4500 PSI/300 BAR tank and the valves popped open allowing the guns to fill.
Giving this reflection, my guess is that the springs on the RAW pistons are too stiff to allow the lighter pressure tanks to open the valves. I haven't decided whether to go back to the Air Arms adapters, trim the springs on the RAW adapters, or see if once the guns are shot sufficiently and the temps warm-up a bit if the problem goes away.
Having a large steel and an Air Venturi 80 CU IN carbon fiber tank, that both have 2900 PSI outputs, I don't really want to give them up over a valve issue.
I will figure out a solution eventually - I just offer this more as an FYI to others that may be considering such a conversion.
DZ
