In Korea, people think water gun is only played by children.
So, water guns are usually product focusing on the characters, not power.
And korean water guns are always use air pressure or piston pressure.
Some korean water guns have good range, but nothing have good output.
In Korea, only barrage,double drench,scatter blast,alphafire,zipfire,freezefire are avilavle that producted at brands.
I want water warriors come in at Korea, but I think it takes so long time.
-I am korean. sorry for my bad English 
If I understand you correctly, you say that some of the Korean-build water guns use air pressure and can get decent range, but not great output. Would you be willing and able to share pictures of some Korean water gun models and let us know what sort of range they get?
ok, I will post it soon.