Thanks guys. I didn't notice the weight on them. The guy at the hardware store said that they were a pound. Now that I think about it I'm not so sure. In the Lyman cast bullet handbook they say that you can heat treat wheelweights from a Brinell of 9 to over 30. What you do is take a few bullets and put them in the oven. Heat up the oven until the bullets just start to show signs of wrinkling. They say to start at 450 degrees. Then back the temperature down 5 to 10 degrees. You may have to sacrifice a few to get the right temp. Then when you have the right temp, put in the bullets for 1 hour. They said that 30 minutes is really all you need and may even work better. Remove and plunge into cool water.
I tell you, that's a hell of a lot cheaper than buying 50/50.
The only reason I want to make 'em harder is for use in Magnum loads. (.357, .44, and .30-06)
Gun control is People Control