A heavier head can help you gain a few yards : Picking up some steam - golf clubs

Golf Digest, Jan, 2000

Can the ol' Cannonball shown here outdrive Big Bertha? You betcha--but it all depends on a few things. In this case, the launch angle could be a determining factor, but according to basic physics, if two objects travel toward an object (say a teed- up ball) at the same speed, the heavier object will propel the ball farther.

"High- speed photos of a club hitting a ball show that the head actually slows down after impact," says Carl Scheie of Wilson. "If a locomotive hit the ball, it would not slow down, because of all that mass. When you have a heavier head and swing it at the same speed as a lighter head, the heavier head is going to hit the ball farther. You can transfer the mass, which will increase the ball's velocity."