What is the recommended temperature pure lead should be to ensure you have proper full out in the mold?

Every mold can be different. I would start at 650º and go up or down from there. I cast with clip-on wheelweights at 730º.

Yes, the mass of the mould blocks, as well as the mould block composition - iron, aluminum, or brass - will determine how well they hold or discharge heat. Not to mention the specific alloy, and the cadence you employ and the technique of putting the molten lead into the mould (bottom pour furnace or ladle and pot). It all has a bearing on your success. Like lightman said, start low and work up until you reach nirvana!

Thanks for the info. I am using Iron Molds and casting 350gr conicals for my ML. Right now I have my Lee pot set for 800 degrees. So far the bullets are the most consistent in weight. Generally, they are under 1 gr with most being around .5 different.

800* is the magic number for pure lead.

Always been 750 for me when molds are up to temp..

I set the temp on my two RCBS pots 25- 30 years ago and never changed them, found the need. Most, if not all, of my casting is is done with lead, tin, antimony. and and a dash copper from babbit metal. Are you casting bullets for black powder?

^^^^^This ^^^^^

I'll second 800°, but that's with a Lyman #2 alloy. Interestingly adding antimony and tin to lead decreases melting temperature. I'd definitely run pure lead at 800°

Looks like 800 degrees is the way to go. As I said, I've had my Lee Pot set for 800 degrees for the last year and found I get more fill out and more consistent weight. When I had it set at 700 my bullets were OK, but not like they are now. The reason why I asked is I was told anything over 700degrees is way to hot???

it's not the lead temp it's the mold temp.

you can cast good bullets with lead from 650 on up

heat your molds more and hotter that will be key.

How do you measure the temperature of the mold?

BBQ temp gauge

Night Owl Enterprises sells them.

or I dip the corner of the mold into the pot to get it hotter.

if bullets are frosty, mould is too hot, let it cool a bit or slow the rhythm of your casting.

bullets wrinkly, speed up tempo of casting or dip corner in pot to get hotter.

Blammer I never heard it said better or simpler...mb