u CANNOT do this with steel or hevi shot or any other hard shot and get away with it.
u can (at your own risk) put bismuth in there if u had to. all the books say that u cant, but many of the loading recipes are the same for both.
the problem with ur idea is, how u gonna get the shell open, empty of shot, re-filled, and re-crimped????? u cant just open up a star crimp, and a roll crimp is even worse to try to open. ull ruin 1/2 of em, and the other 1/2 wont re-crimp well.
u need to invest in a good reloading book, like:
http://shop2.mailordercentral.com/bpica ... er=1131970
then get a loader. like a mec 600jr. you will need a loader to do what u want anyhow