Here's a link to a story about King's friend Dr. Gerald Bull, and his wacky and ill-conceived efforts to build a cannon that would fire a projectile to the moon:
http://www.astronautix.com/g/gun-launched.htmlProof that people are working on the tech doesn't mean it stands a snowball's chance in hell of ever working in a practical and economical manner. All we need is a gun and propellant that can fire a projectile at least 5.6 miles per second... and a projectile that won't burn up in the atmosphere at such velocities. Easy! I wonder why he had trouble getting funding for such valuable research?
Now for something even more deadly, and a technology that actually works, check out this:
https://k61.kn3.net/3/F/F/0/1/8/169.gif.webm