Am I doing this right??

[50 Caliber]

I cast my bullets from straight WW's and have for awhile now. I was told recently that I cast pretty bullets but useless as they are NOT frosty??? He said If I turned the furnace up and cast the same bullet hot and frosty, they would be larger when droped from the same mold and I could size them to fit the barrel of my gun?
Any truth to this?

[wallenba]

They don't need to be frosty. Frosty boolits are just a sign that the mold and or mix, or both, are too hot. There is nothing wrong with frosty, but shiny, well filled out (no rounded corners on driving bands or bases) is the norm. A properly chosen mold should drop them large enough to be sized in a sizing die for the diameter you need, or loaded as dropped. Only until you slug your barrel will you know where to start size-wise. Usually .001 oversize is adequate.

[Poygan]

I can't see any logic to this statement. However, it is useful because you now know to disregard any of his advice.

[btroj]

If they fit now then why change anything?

Absolutes don't work real well in casting.

[dragonrider]

Never had a frosty boolit that came out larger, always smaller, too small.

[MOcaster]

I am not an expert, but with the molten lead being hotter when you get frosty boolits, the lead is less dense, so it will contract more when it cools. It is like when you melt wax, except not as extreme. The hotter your melted wax is, the more it contracts when it cools. It is the simple science of things expand when heated and contract when cooled. So if your starting temperature and ending temperature are closer together, there will be less expansion/contraction, depending on what way the temperature is going.