A bit of a casting rookie here. I had cast some .54 Maxiballs years ago that came out fine by using a dipper and an aluminum mould. My lead pot was rather large as at the time as I had job supplying cast 20lb lead weights to a local company. Recently, I acquired a RCBS furnace with the bottom pour valve. It had some lead alloy that was quite hard in when I bought it and I wanted to cast pure lead for a muzzle loader so I used it up casting .458 slugs which came out very nice. Moulds were iron. When it was empty, I melted a bunch of lead flashing and tried to cast some .45 caliber maxiballs. I had preheated my aluminum mould by hanging it over the molten lead in the furnace by swinging the sprue cutter out to rest on the edge of the pot. Furnace temp was turned to max. My first 20 or so slugs were not quite formed and were returned to the pot and I figured that soon I would be getting good slugs but it never happened. It seems the first few drops of lead into the mould are not filling the mould out like the mould is to cold or the lead is to cold. I cast about 50 but they never got any better. So I'm wondering if I need to add some other metal to my lead to get it fill the mould better (I do want straight lead for the muzzle loader though) or should I go back to the dipper method which I think fills the mould faster thus pouring hotter lead. Also, if I operate the valve with no mould under it, the lead comes out drip drip drip and not a solid stream Is there crud in the valve? What do you folks think?