copper wire source

I had a good purchasing experience from Remington Industries for copper wire. https://www.remingtonindustries.com/uninsulated-wire/bare-copper-wire/ 100' of 16 gauge is $22.82. Free shipping in the US.

I annealed some # 8 copper wire in a barbeque on charcoal briquettes from instructions found here. I've been looking around but I can't find anything thicker. Correct me if I'm wrong but it must be solid # 6, 4 or 2 not stranded to make # 6 etc. It also must be sold by the foot as I don't...