Oh, and as for heavier always being better, it's not true.
Physics lesson,
Energy remaining the same, a heavier slower round will penetrate more and cause a thinner wound channel. A lighter round will penetrate less and cause a wider wound channel.
The desired effect of a round in most situations is to penetrate to a desired depth and stop, leaving all it's energy in the target in the form of tissue damage.
A heavier round has more potential to fly through walls and hit innocent people, while a lighter round will have a higher probability of staying in the target, and causing more damage.
That being said, in general, lighter bullets tend to have more energy because pressure in the gun is relieved more quickly allowing for more powder. A heavier bullet stays in the barrel longer causing pressure to stay higher, meaning they have to reduce powder. The heavier bullets have less energy.
Heavy bullets do have their uses. Most are sub sonic making them quieter, and they can shoot through thicker people better. But lighter rounds are generally more effective, given the same caliber and round type.
Some of you "experts" may disagree with me, but I have been studying and researching this for a long time. A heavier weight or larger caliber does not necessarily equal better. You have to find the result of the equation.