Not just a hotter plate since it is a hollow base. The mould needs to be run fast and hot so the pins don't cool too much. No time for looking at bullets and admiring your work. Cast em fast so mould temps stays high.
YES!That is the idea, hold the mold over the pot and pour heat (alloy) until it runs over the side of the mold for each cavity. Aim at the sprue hole while it's running off the side forcing alloy into the cavity.