No, samurai or their traditional swords, such as the katana, cannot deflect bullets. The development of firearms and the use of gunpowder in warfare emerged well after the time of the samurai in feudal Japan.

Samurai warriors primarily existed during the medieval and early modern periods in Japan, from roughly the 12th to the 19th century. Firearms, including muskets and rifles, were introduced to Japan in the 16th century, well into the samurai era. However, the use of firearms was not a primary focus of the samurai's martial arts training or combat tactics.

Traditional swords, while effective against bladed weapons and in close-quarter combat scenarios, are not designed to withstand or deflect the impact of high-velocity bullets. The speed, force, and small size of bullets make them extremely difficult to deflect or block with a sword.

It's important to note that the introduction of firearms, such as muskets and rifles, marked a significant shift in warfare strategies and led to the eventual decline of traditional samurai warfare.

If you are interested in learning more about samurai, their martial arts, or the history of firearms, I recommend consulting reputable sources or seeking guidance from qualified instructors or historians.