The answer to this question depends on the distance at which you're shooting At close distances (50 ft), the slow heavy bullet will hit higher because it's launched at a steeper angle. However if you look at the trajectories out to 100 yds, the heavy bullet will cross the path of the light fast bullet and hit lower at the longer distances. There will be one distance at which the 2 bullets have the same point of impact.

Gravity has exactly the same effect on both bullets; they fall at 32 ft/sec/sec independent of their weight (Galileo showed this in the 16th century at the Leaning Tower of Pisa). The difference in trajectories comes about because the heavy slow bullet takes longer to get to a given distance and is subject to the downward force of gravity for a longer time. My Freshman Physics Professor demonstrated this in a way I haven't forgotten in 61 years - he had a 4 foot long glass tube with all the air pumped out of it and a silver dollar and a feather inside. He would hold the tube up vertically and quickly invert it and the feather and silver dollar would fall and hit the bottom together.