I've made a line launching gun out of PVC.. 3 inch, 1 ft long for the resevoir, end cap, and a reducer completeling it, a pvc ball valve, then chose a cliber...

I'm sure you can go from there..
Gage from Harbor Freight, schrader valve for filling... I've gone from 15 psi for a short shot, (60ft high over a samll tree) to 75 yds, at at least 125 ft high with 70 psi.. Look up potatoe gun and scale accordingly...
I use mine with pvc end caps and coupler, for throwing lines over trees for wire antenna supports... best system I've ever used in 25+ yrs as a HAM...
The ball valve does dump all the air, but refilling is easy..
73
Semper Fi
Ed