The "Panjagan"

The Panjagan is described as a weapon that could fire 5 arrows at once.
Panj (Middle Persian)=Five.
This was used to devastating effect by the Sasanian Persian army against the Gok Turks in 619 AD.

Thinking how a regular bow could fire 5 arrows at once to any effect is baffling.

However in China a repeating crossbow was invented around the year 200 AD by the chancellor of the Shu Han dynasty, Zhuge Liang. Although similar crossbows are said to have existed before, Zhuge improved the design and fire rate of this weapon.

So what about the Panjagan? Well it might have derived from the weapon Zhuge created.
How did Chinese end up in Persia?

In 263 AD The Shu Han lost to the Wei dynasty and many people of all classes fled the capital city Chengdu and other regions westwards, along the old Silk Route, to Persia.
At that time Persia would have been glad for such reinforcements as it too had a new dynasty, the Sasanian which, by then, had been in power for 39 years with almost continous war with Rome.
If the Persian armies were not fighting Romans they were fighting off the Turks who began raiding the eastern regions of Persia from 483 AD.

This weapon, and no doubt the well drilled Savaran cavalry, kept the Turks out of Iran until the fall of the Sasanian empire in 651 AD.