Steve Brooks mold.

[Don McDowell]

You also need to use a ladle that holds enough melt that it would cast a couple of bullets, but don't use all of it, just enough to pour the bullet and a good sprue on top.
That's the biggest problem I have with the vented sprue plates they dribble to much melt back into the pot.
Keep the alloy at 775 or so, and for what ever reason the Brooks moulds can deal you fits if the sprue plate is to tight.