That's not PA...that is MQ'd. He is using an Eblade from a cocker. They put an MQ valve in it..which makes it a true electro pneumatic...he can just continue to pull the trigger and it will fire, whether or not he moves the bolt at all to feed. He just only needs to pump to load paint and fire immediately. This requires batteries obviously
A PA or Pneumatic Assist works by attaching cocker pneumatics to the pump, so it's a pnuematically operated pump like a cocker. Only the cocker attaches the three way to the trigger, here it is directly connected to the pump. So your pump stroke is only 3mm or 4mm long...if you have an auto trigger you can just RIP off shots. It is fully pneumatic and mechanical. Docs Machine has pics of some he did with a phantom
Watching that vid.....did anyone else notice how wobbly the whole marker was? Especially when watching the barrel? Seems to me that that system would would not contribute well to accuracy.