Armor upgrades just arrived

What if instead of extra armor, they ask the enemy to stop shooting at the airplane? They save on ammo, we save on armor, win win.

What was the line that made it through the armor on the underside? The one on the right side must have been a ricochet given the timing variance and lack of exit profile. The first on the left has a profile like the rest.

At least it's not right up on the leading edges.