No, a katana or any traditional sword is not capable of effectively deflecting or stopping bullets. The speed, force, and penetration power of bullets fired from firearms far exceed the resistance and durability of a sword blade.

Bullets travel at extremely high velocities and are specifically designed to penetrate targets. When a bullet impacts a solid object, such as a sword blade, it can easily penetrate or pass through it, potentially causing harm to the wielder.

Attempting to deflect or block a bullet with a katana would be extremely dangerous and ineffective. The momentum and kinetic energy of a bullet would likely overcome the strength and structure of the blade, potentially causing severe injury or death to the wielder.

It is important to recognize the limitations of traditional weapons when it comes to dealing with firearms and bullets. Firearms represent a significant advancement in warfare technology that emerged well after the time of the samurai and the development of traditional swords like the katana.

If you are concerned with personal safety or self-defense against firearms, it is advisable to explore appropriate modern self-defense measures, such as seeking shelter, utilizing cover, or, if legally permitted, employing firearms or other contemporary self-defense tools specifically designed for that purpose.

Always prioritize personal safety and follow the laws and regulations of your jurisdiction when considering self-defense options.