Bullets have lots of concentrated qi. ๐ Far more than fists, swords, spears, crossbow arrows, or anything that iron shirt was developed as a defense against. Many accomplished but not perfectly accomplished people learned this during the Boxer Rebellion. Theoretically I suppose one could become adept enough to stop bullets, but unless you can already stop spears and other such forceful pointy objects, that’s probably a bit aways. ๐