So the actual definition of the expression bulletproof, comes from a medieval and older tradition of testing weapons on finished pieces of armor. So a master armorsmith might strap his finished creation to a dummy, and then have his assistants hit it with the various weapons it was supposed to defend against.
Arrows, halberds, swords, axes and the like. This would damage the armor slightly, but it also give it a reputation for quality, since you could see it actually worked. This was called a proof. Much like a scientific proof.
When firearms became more popular, the same thing was done with them. They would be shot with a contemporary firearm (usually a pistol) and the mark would be left to show that the armor could indeed defend the wearer from such a shot. This mark was called the bullet 'proof'.
![[Image: IRoWkSz.png]](http://i.imgur.com/IRoWkSz.png)
![[Image: rMWrq6V.jpg]](http://i.imgur.com/rMWrq6V.jpg)
So armor of the day could certainly stop firearms. The general rule for plate is:
1) It will always stop ricochets and shrapnel
2) It will always deflect glancing hits
3) It will stop pistols at any range
4) It will stop muskets/rifles at long range
Arrows, halberds, swords, axes and the like. This would damage the armor slightly, but it also give it a reputation for quality, since you could see it actually worked. This was called a proof. Much like a scientific proof.
When firearms became more popular, the same thing was done with them. They would be shot with a contemporary firearm (usually a pistol) and the mark would be left to show that the armor could indeed defend the wearer from such a shot. This mark was called the bullet 'proof'.
So armor of the day could certainly stop firearms. The general rule for plate is:
1) It will always stop ricochets and shrapnel
2) It will always deflect glancing hits
3) It will stop pistols at any range
4) It will stop muskets/rifles at long range
