This is a video from the 'Man at Arms' Youtube series (previously: Link's Master Sword) featuring blacksmith Tony Swatton forging Thor's hammer Mjolnir in real life. He doesn't actually use the heart of a dying star though (hopefully for reasons obvious to you), instead opting for a hollow 20-pound version. Still, a 20-pound hammer -- that could do some serious damage. Hopefully to my neighbor's car until he learns to stop blocking my driveway.
Hit the jump for the video, but skip to 6:00 if you just want to see it breaking things. Tony mentions at the end of the video that he's going to fill the hollow head with lead shot to push the hammer's weight to ~250-lbs so nobody will be able to pick it up if they come to see it in his showroom in Burbank, CA.
Thanks to Marcus, who knows a thing or two about munitions. No? Different Marcus? Damn, because I had some questions about Mad Moxxi.