A list of 18th century cannon projectiles (and tools).
You can see the early versions of grenades and grape shot (I didn’t know grape shot was used so early on). I’m very puzzled about the chain shot though. It doesn’t seem like it would be effective in any way, especially if one wanted to hit anything with accuracy or get it out of the barrel with any speed (it might even make the whole cannon blow up) unless you used copious amounts of black powder. Even then having a loose chain and two balls rattling down a barrel seems like a huge safety hazard to me.
According to ye olde Pedia of Wiki, chain and bar shot were naval munitions for cutting sails and masts of opponent ships. Chains could be as long as six feet, increasing the chance of causing damage to a ship over short-distances (because as I predicted, they were ridiculously inaccurate). Here are some pictures from aforesaid site:
French chain shot:
These projectiles died out with the development of iron-sided warships.
and also via