One shot stopping power revisited
From Rutherford B. Hayes's Diary & Letters page 534 we have an interesting example of the failure of one shot stops
One boy in the Twenty-third was shot in the face. The ball entered near his nose and passed over or through the cheekbone up towards the outer corner of the eye. The surgeon thought it was a small bullet and fearing it would injure his eye to probe for it, let it alone. He got along very well for three weeks, when they cut it out near his temple. They were astonished to find that it was an iron grape-shot over an inch in diameter - as large as one of your India-rubber balls! He is well and never did suffer much!
Vigilantibus et non dormientibus jura subveniunt. Molon Labe!