Thanks for the replies. Seems to reflect my experiences that filling seems a bit hit and miss (bit like shooting) as to whether the shop gives a good fill. I have used a dive shop near to Milton Keynes and they would put the tank on to fill and then say pop back in 30 minutes. They said that they needed to make sure the tank had cooled in the water thank Always got a good fill of air from them. That was for a 3 litres tank. Fill time at the dive shop that I have been using can be between a 5 minutes and 10 minutes for a 12 litre tank. Will Shooting Supplies fill a 12 litre tank?