I assume (but only an assumption on my part) that the Alsafe 700cc bottles are now showing up at U.S. vendors for those who do not wish to buy directly from the Chinese manufacturer.
I found what I consider to be a reasonable 'special' price for them ($200 + shipping) at Ares Airguns Tactical. Maybe the least expensive way to buy these if you are only looking to get one or two. And they appear to currently be in stock.
https://www.aresairgunstactical.com/Air-Cylinder_c_185.html
Remember that for mounting to an FX gun you will also need a valve - either the one off your old bottle or a new one directly from FX USA ($55 + $9 shipping the last time I bought from them). You just need to call or email FX USA for them to provide you an on-line invoice to pay. These bottles have the 'standard' M18x1.5mm threading, so for other guns (Daystate, Brocock) they will mount right onto the gun's action without needing a valve or an adapter. For other guns, make sure to check what the correct OEM bottle thread is on your gun.
I found what I consider to be a reasonable 'special' price for them ($200 + shipping) at Ares Airguns Tactical. Maybe the least expensive way to buy these if you are only looking to get one or two. And they appear to currently be in stock.
https://www.aresairgunstactical.com/Air-Cylinder_c_185.html
Remember that for mounting to an FX gun you will also need a valve - either the one off your old bottle or a new one directly from FX USA ($55 + $9 shipping the last time I bought from them). You just need to call or email FX USA for them to provide you an on-line invoice to pay. These bottles have the 'standard' M18x1.5mm threading, so for other guns (Daystate, Brocock) they will mount right onto the gun's action without needing a valve or an adapter. For other guns, make sure to check what the correct OEM bottle thread is on your gun.