Eek! We will keep this in mind while prototyping shooters.
Reminds me of our original shooter design last year. We had two CIMulators driving a chain with a two to one gear ratio, and we got our shooter spinning at over 8,000, and then the chain broke and flew forward...
... luckily, we had used C-channel to make an enclosure to make sure the chain couldn't go forward more than an inch
I can't imagine what would have happened to whomever was in front of it if we hadn't had a chain guard.