Where to find and do I need antimony?
I cast straight WW's for those calibers. I add 24" of 1/8" solder 95% tin and 5% antimony to the bottom pour pot when I cast. That will work fine for what you want to shoot. I only add the tin to help the lead fill out the mold better, the bullets came out with a lot sharper edges with a little tin.45acp and 9mm right now.