Ideas on items as scrap lead and where to buy? For slug reloading

[NinjaHunter]

Hey guys,

I'm trying to get into slug reloading. I bought a lee 4-20 smelter, moulds and etc. Also watched youtube videos about casting slugs.

However, the one thing about slug reloading that keeps eluding me is: what items constitute as scrap lead? And what type establishments should I visit to find scrap lead to buy?

As for my location: I'm in Edmonton.

I'll appreciate any input on your guys' part