Governor, history is profuse in narrating epic episodes in that a handful of dudes defended a post from the assault of a zillion foes.
We know of some that would put Leonidas far back in the queue for the Guiness
. I gather that, the difference between facts and myth often resides in the ratio of combatants allegedly registered in either side.
The ammo business ...
Grapeshot and shrapnell were both (also) used in the Peninsular war, together with canister, which curiously we call lanternetas (small lanterns). Wellington was not fond of shrapnell, which he personally checked that its effect wasn't lethal enough; plenty wounds but ... not deadly as should. He saw General Simon being hit by shrapnell in his face and head; the bullets were removed like it is done when one accidently gets hit by birth shot in the face whilst duck hunting (SIC); not actually seriously wounded. When he heard that in Badajoz they used such grenades with the 24 pounders as a solution, he ordered that cannons of equal caliber were loaded with musket balls, to obviate such system flaws and ensure that the wounds did in fact incapacitate the ones that received them.
One not so talked about apparatus that became a latter occasional addition (1823-1814) in this war was the explosive rocket, invented by Baronet Sir William Congreve.