Soft lead pours so much easier than hard lead. You can order soft lead but it's expensive. Some easily accessible forms of soft lead are plumbers lead (pipe, barrel traps), roof jacks, and sheet lead. These can be obtained through metal recyclers or construction guys. Hard lead which is generally wheel weights (ww) can be obtained from recyclers or tire shops. Most bullet lead is ww as are unlabeled ingots from tackle suppliers.
WW is usable, it works better cleaned or fluxed. I've found that it's best to crank up the heat and use hot molds. WW is an alloy lead, it has some different metals and is generally pretty dirty which can cause some problems when pouring. Hence my pouring suggestions. After some experimentation I've found some good mixing applications and reasons for doing so. With smaller things this can be some good info since ww lead clogs up spouts and molds.
If you can find some soft lead you'll pour those smaller heads so much easier, but a mans gotta do what a mans gotta do with what he has. I hope this helps and good luck.