If you want a noisemaker, can I suggest getting a big speaker.
Less flying limbs, less screaming and less blood.
I'm not being negative, but those barrels aren't safe.

If you were to research this more, can I point you to http://4hv.org/news.php

It depends, if budget allows and you have a 12v battery, try a car tyre
pump. If you don't want to have to depend on a car battery, ask
at a bike shop. They should have a pump that will get 100PSI.
I'm not referring to a shock pump but a good one is worth about
$15 AUD $10 USD.

Just because your bike pump says it will do 60 PSI that does not mean it cannot do more. Also for that pressure copper is overkill so 1/2 inch PVC shoud do. I'm not going to tell you to use sprinker valves or piston valves but they will help. If it work for what you want there is no reason to upgrade.

TwitchTheAussie wrote:God bless the backyard of rural australia. I like it dude. Its hot. Nice work.

Hear Hear.
Also hyldgaard, you have the same blowgun as me and I am in
Australia.