Martin, was looking at your old post on .410 flares. I don't know of any source but Orion has a large selection of various flares including a good looking 12 gauge flare. Take a look:

http://www.orionsignals.com/Marine/Products/aerial.html

They make some good hand held flares. I bought a bunch at WalMart when they discounted them. They would definitely get someone's attention. As I remember, they were about four or five inches long and about the diameter of a 12 gauge shell.

Fairly easy.

Making a reliable one, with predicatable burn time... not so easy. Particularly considering your package.

Martin, in looking over the Orion page a little closer, it says the 12 gauge flares are to be used in a 12 gauge launcher . If they were fired in a shotgun the length (of the flare) might exceed the length of the chamber and cause the barrel to go boom so I suspect they should NOT be used in a shotgun. I post this for the benefit of the shotgun impaired folks. Don't want anyone to get hurt from reading this. <img src="/images/graemlins/crazy.gif" alt="" />

What's his package got to do with making flares???

Sorry... just...couldn't...re...sist <img src="/images/graemlins/blush.gif" alt="" /> <img src="/images/graemlins/shocked.gif" alt="" /> <img src="/images/graemlins/smile.gif" alt="" /> <img src="/images/graemlins/laugh.gif" alt="" /> <img src="/images/graemlins/wink.gif" alt="" /> LMAO