Since many of us use lathes for our projects, I thought I might tell this story here...
Day before yesterday, an employee in the shop where I work was polishing a pin in a large lathe at ~2000 RPM. He used a cloth shop rag to wipe off the grit while the spindle was on, rag wrapped around the pin and the ring finger on his right hand was twisted off at the first knuckle (about 1" from the tip).
When he came to me, he had the finger still wrapped in the rag. Doctors at the hospital were not able to reattach it.
This is a smart guy with 20+ years' experience in the shop. He appears to have been in a hurry, and broke a safety rule. He may have done the same thing thousands of times without ill effect, but this time it got him.
It could have been much worse - I read an accident report some years ago where a similar thing happened to a guy, but his entire hand made about three revolutions before the rag ripped free. His hand, wrist and forearm were badly damaged and he never regained much use of them even after multiple surgeries.
Don't take safety shortcuts when dealing with cannons OR powerful machinery.