"I suppose it's possible to kill oneself, at very close range, with a blank round."
Indeed it is. Bob Monkhouse very nearly did it to Charlie Drake. As it was he only shot off part of his ear.
Extract from h2g2 site
But it was TV that was to make Bob Monkhouse a family name for the next 50 years. He became the first comedian to be under exclusive contract to the BBC so he made a lot of guest appearances in variety shows. In 1954, he and Dennis Goodwin made Fast and Loose, a sketch show with guests, until he shot Charlie Drake's ear - but in true show bizz style, the show went on until the curtain closed and Charlie passed out.