I had this idea since last summer, but didn´t have the courage to build it, as I don´t know if it will work

So here it´s a diagram, now my worries are:
1. No enough air to shot all the bbs, even with high pressure chamber
2. Only part of the bbs will be launched, rest remains because all the air has scaped by firing part of the bbs;
3. Low range.
But in case it work, it would be a brutal airsoft ammo, imagine fire it with a homemade combustion grenade launcher, it will be possible to hit hidden targets (behind a tree for example).
The diagram it´s just a idea, the body would be made out of soft wooden material, like cork. Also it would be aerodynamic.
For internal, I´m thinking about aluminium, as it´s light than brass.