wow, I've never seen that before. Pretty impressive(reminds me of Perfect Dark
) Unfortunately, we're dealing with pressure, so we've got to have the seal. Perhaps if you took mechanicalbrain's bolt idea, and simply used a spring magazine, you'd be able to pull something similar off.
Edit------------------
If you meant using the actual crossbow to launch the t-shirt, that would definitely work. Seems like an indirect way to throw em though. ( pressurize the same volume of air to compress the bow, instead of just using that air to throw it. Besides, it makes a loud boom!
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