I think cannister shells were the next evolution of it.

Although your description of what it was used for, is correct. I think you will find that Grapeshot was used by the British way before the American Civil War. Originally posted by ✯Comrade Tiedanski 五月天:Shrapnel evolved from Grape shot( shooting little balls like a shotgun from a cannon ), the earliest was used during the US civil War, Boshin Wars from what I can recall, it was massed used during WWI where these shells filled with metal shards would explode in proximity and raining metal shard in an array of area( although sometime it will just plunge to the ground and explode like a grenade ), the shrapnel effect would usually lead to some nasty wounds or amputees in which it's very unpleasant to be struck by them especially during WWI. But in war thunder, shrapnel has nothing to do in that direction or capturing ships or even board, better to use HE than shrapnel in War Thunder for ships, I can see shrapnel might be useful in taking crew members of boats and gunboats in-general, but HE is still more reliable tbh. The only time I can relate shrapnel being effective is when you try to capture the ship/boat your attacking by disabling the crew members while keeping most components intact for you to operate. Shrapnel in-general is used as an Anti personel shell where you scatter fragments of metal shards across an array of area( quite useful when dealing with planes tbh with proximity fuse), while HE shells fire and explode upon impact causing structural damage and personel causalties, the Shrapnel would sometimes explode in mid air( before they added a fuse cap ) and rain metal shards upon the crew causing mayhem and panic overall, HE is used as an soft structual demolition shell while the Shrapnel is used for Crew men on board.

Swedish navy war thunder