MrCrowleys GB cannon, Built by me, Update: Fixeded

[Northir]

anyways i put the old piston back in for now until i can find the lightest toughest best piston, that someone can make, not that HDPE ive been lookin into different kinds of foam, epoxy and other shit that people can mix up at home, will post them in a new thread when i find something that works well

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lets try not to break more good cannons though eh?

[psycix]

You can extend the barrel into the tee so the piston is behind the hole.

On high-performance launchers, this may cause some flow restriction.
Not that it is a bad thing or so, you can still have a very powerful launcher, its just to squeeze out those few extra joules.