What am I doing wrong?

[Le Loup Solitaire]

I would suggest working with increased heat and getting 1-2% tin into the alloy after making sure that the mold cavities are well cleaned. I would use a good solvent like acetone to make sure that any hydrocarbon based substance is thoroughly removed from the cavities and the mold block faces. Making sure that the melt is fluxed and well cleaned also helps. Molds should be pre-heated prior to casting and a number of casts are necessary to get things up to speed. LLS

[AR15Buffer]

Thank you for all the great responses. The mold is a single cavity aluminum mold. I use a Lyman thermometer that sits in my Lee pot. I was using 2 cycle engine oil as a lubricant.
I will definitely put to use all of the suggestions on the cleaning of the mold, increased heat, and slowly get it right.
I spoke to a friend earlier this evening about picking up several lbs of sawdust from him tomorrow evening. I will put that to good use.
Bryan

[Moonie]

Thank you for all the great responses. The mold is a single cavity aluminum mold. I use a Lyman thermometer that sits in my Lee pot. I was using 2 cycle engine oil as a lubricant.
I will definitely put to use all of the suggestions on the cleaning of the mold, increased heat, and slowly get it right.
I spoke to a friend earlier this evening about picking up several lbs of sawdust from him tomorrow evening. I will put that to good use.
Bryan

Sawdust is great to use, I also use one of the commercial size paint stirrers you can get at the hardware store.

[AR15Buffer]

Today I got back on the horse. I brought the pot up to temp. Added cedar sawdust that I picked up today for free from a business that builds custom doors and windows. I let it smolder until it was all burned (black), then I stirred it in and then removed the dross that formed on top. There was quite a bit. I did that twice, then put sawdust on top and let it sit throughout the casting session. I only did approximately 10 lbs of lead before I called it quits. I ran the temp a little hotter than on Tuesday. It seemed to help quite a bit.
Prior to casting, I once again cleaned the mold with dish detergent. I will look at the boolits in a few. I may have to pick up some acetone to really clean the left side of the mold. That side is the one that seems to leave a shadow on the bullet. I will sort that out given time.

[AR15Buffer]

Attached are pictures of today's casting session. I still have some work to do to get where I want. It was rewarding that I saw an improvement over Tuesday's casting session. I will hit it again tomorrow evening. Thanks for all the detailed replies and suggestions.

[Tar Heel]

Well done. Just remember that even after 30 years of casting, some days just don't work. The casting Gods are conspiring against you sometimes! When you have one of those days and you start chasing your tail, just turn everything off, clean up, and come at it the next day.

[Psypher]

A wise member here told me this...

Temp up until frosting of the bullet occurs, then back it off and you will be just right.

[Pilgrim]

It looks like you have gotten most of the crud out of the melt as I don't see the inclusions that were showing in your first photos. However, fluxing again wouldn't hurt. If your band edges are not sharp, it is often due to a venting problem. Make sure the vent lines are as clean as the cavities. I occasionally use a razor blade to "trace" the vent lines just to make sure they are open. It doesn't take much blockage to screw things up. If the base of the boolit is not sharp all the way around, the sprue plate may be too tight. The boolit base is vented between the mold blocks and the sprue plate. Finally...you might have to take up peeing on flat rocks as thatsometimes is necessary to ward off the lead gremlins! FWIW Pilgrim

[jimb16]

When I saw you mention the 2-cycle oil, I figured that was the problem. Jt thins out and gets into the mold. Those bullets looked like they had oil "pollution" in the cavity. It will eventually burn out, but it is better not to get any oil into the cavity in the first place. The shadow on the boolit may be caused by residue from the burned oil.