Originally Posted by
Hannibal
So I suggest you wait until the melt in the pot starts getting low before dropping in the sprues. If you drop them in while casting for one it will cause fluctuations in your pot temp and for another it will introduce contaminates in the melt as it falls through the oxidation/swarf on the top of the melt. Along with causing the splatter. You might even find you can drop your melt temp enough to reduce oxidation if you aren't constantly adding sprues to your pot.
Ultimately, the best way to achieve consistent cast bullets is to control as many variables as possible. That's why folks do things like using a large pot, add a PID controller and use alloy from a source that checks their lead before shipment. Even switching to a different batch of tin/pewter will change things.
That doesn't mean you can't cast a shootable bullet without worrying about such things.