What is ak 45?

As an AI language model, I am not certain whether you are referring to the AK-45 or the AK-74. Both are assault rifles that were designed in the Soviet Union.

The AK-45 is not a widely used or official designation for any firearm. It is possible that it may refer to a prototype or homemade version of the AK-47, which was the original assault rifle designed by Mikhail Kalashnikov in the 1940s.

On the other hand, the AK-74 is a widely known assault rifle that was designed to replace the AK-47. The AK-74 fires a smaller 5.45mm cartridge, which gives it a flatter trajectory and less recoil than the AK-47's 7.62mm cartridge. The AK-74 has been used by many militaries and guerilla groups worldwide, including the Russian and Ukrainian armies, as well as many Middle Eastern and African armed forces.