History channel did a show on the weapons used at Agincourt. How longbows were made, what wood they were cut from, was an English archer able to have five arrows in the air at once, etc.
The arrows were designed to be armor-piercing with a heavier than normal warhead (?) that imparted greater momentum. Launched by longbow with a high trajectory, these English arrows pierced French breastplates with great effectiveness.
The French had Venetian crossbowmen whose bolts were also effective against plate armor but they took much longer to recock using a two-handed winch. Advantage: England.
Those would be bodkin points.
**The arrows were designed to be armor-piercing with a heavier than normal warhead***
Henry VIII ordered his troops to coat the tips of arrows with goose grease to make them go through enemy armor better.
And to think, our modern anti gunners went ballistic over teflon coated bullets designed to protect the bore of the pistols rather than increase armored vest penetration.