Quote Originally Posted by iwalk View Post
Do you have to fill a Bottle then use that to fill a rifle?

If you can directly fill the rifle cylinder, then you save the price of a dive bottle.
I will let other work out the maths for that.
The cost of the cylinder has not been included
It's comparing the cost of refilling a cylinder you already own, to buying a pump which then saves the refill costs.

Some people DO need to fill a cylinder because they only shoot away from home & need to refill the rifle during the day (& in that case the cylinder still needs to be tested)

What I do not know is whether these pumps provide DRY air, certainly they don't have filter packs built in, although they sell them at about £160,
so I suspect they might just use a centrifugal/cyclone moisture trap which will reduce moisture content, but is far from DRY.