this is where i decided to put it since its easy to get to and since i will be getting a new rear bumper with tire carrier the extra wieght should be fine on the gate just hope the sheet metal holds up im trying to figure out to reinfrorce might just tack on some extra sheet metal

 

just don't USE it horizontal like that.
Liquid CO2 in air tools = BAD

only thing I would add is another strap near the top of the cylinder to handle that and it should have no issues at all.