Some simple physics can be applied her. The aim is to get as much speed and energy into the line on the forward stroke. For the acceleration, force = mass times acceleration, so more force = more acceleration. But also for the same acceleration you need to put in more force for a given mass (weight). The greater the acceleration, the faster the line will be travelling at the end of the forward stroke. However, you also need to put as much energy into the line to maintain the speed and get the distance. Energy = mass (weight) times speed times speed. So for a same speed, the heavier line should travel further. However, from this, the speed of the line is more important. A line speed of 2mph has 4 times the energy of a line speed of 1mph, 3mph: 9 times. So technique is all about getting the maximum speed of the line at the point when you shoot the line forward from the same amount of force. You can overcome poorer technique by using more force.