soapstone can be found in any shop that sells welding supplies. It is the standard for marking on steel. used to buy it in bricks for the guys in the shop. the sticks come in at least two thicknesses and round sticks that fit into holders.
go into the store- they might just give you a piece or two if they have some snapped from dropping.

I've been using a dab of beeswax, but I like the idea of soapstone so I order a couple pencils from Amazon.

The reason for my original post was galling on the top and bottom of the mold and the dual sprue plates. 
At that point I had cast 3 or 4 dozen bullets when the sprue plates suddenly felt like there was sand in the working surfaces. 
I took things apart last night, stoned away the offending burrs on blocks and plates then polished the plates with 320 on my milling machine table. I sprayed everything with brake cleaner then followed with a bath in fresh acetone and a blast from the air compressor. 
It's a steel mold with steel plates.
I rubbed soapstone on all the mating/working surfaces, spritzed a little graphite at the pivot points of the washer and the bolt head.
I made sure the through bolt for the pivot had some end play, therefore didn't even touch the sprue plates and that they swung freely.
A dozen bullets into a casting session today had it feeling sand filled again.
I only use certified lead/tin alloy. I stopped using wheelweights years ago due to all the garbage that seemed to be getting in the mix. 
I think this answers the questions and comments made. 
If I had a pond I probably would have tossed the hot mold into it just to hear the sizzle.