Looks like OP found bar shotFrom Artillery Through The Ages (1949) - a very useful little reference:
View attachment 2102771
Slightly OT - Note the difference between grape shot (iron) and canister (case) (lead). Generally, ships used grape and land artillery used cannister, despite the famous phrase "a whiff of grape."
Good luck to all,
The Old Bookaroo
Where did you go to ID it? Just curious because I don't recall ever seeing one with an octagonal bar,ID to the Revolution war bought for $5 sold for $1000