Mounting the tankdirectly on the rail horizontally?

[canadaguy]

I am wondering what the term is for when you mount the tank on the rail horizontally using those to screw holes at the back. what is this called? also what screws do u need for it? thanks alot.

[jeffremiller]

Back Bottle? Is that the correct term?

Here's the correct part to do it with...

http://store.airgun.com/acb/showdetl.cfm?&DID=17&Product_ID=216&CATID=6

[FeelTheRT]

back bottle is it. That's old skool.