HHHMMM. How long is a piece of string?
First thing to decide is what is your time worth.
Then, assuming you charge for your time and the alloy used and not for things live electricity, depreciation of equipment etc you multiple it out.
EG:
You can probably do 2 pours per minute with the 6 cavity mould once everything is hot. That's 12 bullets a minute or 720 hour.
If you charge out at $20.00 hour then divide this by 720 for 2.78 cents each for labour.
Add the cost per bullet for alloy and your there.
Now, is your rate competitive with the market?
Are you going to size and lube?
Do you sort them for defects?