Now then
it's a Air arms s400 carbine, does the make and model change the pump to get?
ta
mate there is no difference between them,they will all take the same effort.
you will have a fill probe that fits to the pump and all pumps have same size hose.
I would suggest you get a used diver's bottle as I wrote above.
Cheers for the help,
going tomorrow to get the pump
ta