Bullet making and shooting are great fun, it's just a different world from jacketed. One point mostly overlooked is that hardness of the alloy is not the most important thing, bullet fit is king. Slug your bore with a soft lead slug and size your bullets .001-.002" over groove size, you won't have problems with leading. I regularly drive my bullets in my .357Max rifle over 2000fps using gas checks or paper patching with no problems. Most people are still using wheel weights for a lead source, but bear in mind that lead WW are going the way of the dodo, the tree huggers are to blame, but there are many sources of lead, such as your local scrap yard, or a place called Rotometals on the internet, its just not free. May I suggest you visit
www.castboolits.gunloads.com for more info than you can digest at one time. Enjoy your new hobby. Goatwhiskers