Chain shot (aka "dismantling shot"), and the whole "French fire high" thing was considered more of a method for disengaging than making an opponent more vulnerable to attack, particularly in fleet actions. On the short range aspects of chain, there are certainly some very interesting physics effects going on there once the two ends of the "chain" start tumbling and interfering with each other, nit to mention the greater drag over and above that for a standard round shot. It may also be worth mentioning that chain (and bar) was also fired low as it had greater effect on crew and light wooden upperworks, and it was also occasionally used on land