Advice on filling a empty gun off divers tank

[angrybear]

Ok. When i open the tank it shows the tank pressure.when i close it it should show the guns tank pressure. When i shut the valve it aint showing the guns tank pressure. Thats why my A hole is twitching as i dont know what pressure is in the gun. Both guns aint showing any pressure so could there be a fault on the divers tank regulator?

Er not quite,

Firstly you need to close & seal the circuit, that can be with a blanking plug, or by fitting the rifle to the end of the hose.

Now when you open the cylinder valve the gauge on the cyl will show the back pressure in the hose, up to the pressure that is in the cyl,

if that pressure exceeds the pressure in the rifle it will force open the rifle fill valve and you will hear the air flow in to the rifle.

As the rifle fill valve opens you should see the cyl gauge flick down to whatever the rifle contains & while filling the cyl gauge reads for the whole system including rifle.

When you close the cyl valve the gauge reads what is in both the hose & the rifle, and should hold that pressure until you vent it,

then you open the vent to drain the hose so that it can be disconnected & the cyl gauge drops to zero.

Obviously, you cannot fill the rifle with more pressure than the cyl contains & at every rifle fill the cyl pressure will drop until it to needs a refill.

Also you keep saying 'regulator', when it probably isn't one, which is pretty confusing.
a regulator is a device to control the amount of pressure that comes out of a cylinder it will have two gauges one for the cyl pressure & one to set the outlet pressure.

The cyl has a 'Valve' to open & close which on a surface cyl has a gauge & bleed valve built in to it,
or on a scuba tank without a gauge, you should have an Airgun Adaptor which has a gauge, bleed valve & the hose which fit to the cyl outlet.