In 1753, the "secret howitzer", a special gun with an oval bore—intended to spread shot even wider—was briefly introduced into Russian service, but ultimately proved unsuccessful.
[citation needed] The United States Army developed a canister round, the M1028, for the M1 Abrams' 120 mm smoothbore gun in time for the 2003 invasion of Iraq.
In addition it can be used to create entry points to buildings, reduce wire obstacles and clear heavy vegetation, as well as strike low flying aircraft and helicopters.
Rounds recovered from Henry VIII's warship Mary Rose (sunk 1545) were wooden cylinders filled with broken flint flakes.
Canister played a key role for Union forces during their defeat of Confederate troops in Pickett's Charge during the Battle of Gettysburg in July 1863.
[6] At times, trained artillerists would fire the canister shot towards the ground in front of advancing enemy troops, causing the conical pattern to flatten out as the balls ricocheted and skipped off the terrain.
Artillery on Seminary Ridge skipped canister shot at Alfred M. Scales's approaching Confederate infantry, breaking up their attack and forcing them to take cover in a depression.
Canister shot was also used to good effect by U.S. Marine 37 mm anti-tank guns in World War II to break up Japanese banzai charges.
[9][10] Grapeshot was a geometric arrangement of round shot packed tightly into a canvas bag and separated from the gunpowder charge by a metal disk of full bore diameter.