RSSPopSci has an interesting feature and video on making your own ammo, it's as simple as pouring it off a roof :)
About 230 years ago, molten lead that rained from the sky--historically something to avoid at all costs--became a clever new way to manufacture an important commodity: shotgun ammo.Precisely round pellets fly straighter, but casting each in its own 1/8-inch mold isn't exactly mass production. In space, making them would be easy. In zero gravity, surface tension pulls any liquid into a sphere, the shape with the least surface area for a given volume. This is as true for molten metal as it is for drops of water floating inside the space shuttle. On Earth, the closest thing to zero gravity is freefall--falling objects experience weightlessness right up until they hit the ground.
Now we some propellant, a primer, some sort of case to hold it all. Then we have ammo.
The next thing the manufacturers do is trickle the shot down a shoot where the shot is free to fall off the edges on the way down. The shot that makes it all the down the center is collected as the good stuff and the rest is sent back to the melting pot.
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"falling objects experience weightlessness right up until they hit the ground."
This is just completely false. Why do you think falling objects fall?
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There was a TV programme called "Local Heroes" a while back, hosted by Adam Hart-Davis. The programme on Bristol showed how lead shot was made by dropping molten lead off the roof of St Mary's Redcliffe church. A shot tower was built just across the street, and stood there until the road was widened in the 1960s. A modern concrete shot-tower still stands in central Bristol, but has been converted into offices. People aren't so keen now, on dropping molten lead from towers in the city centre; some sort of health and safety thing...
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