The origin of the name Pistol?

edit

I have long been curious as to the origin of the name Pistol in Shakespeare but no explanation is currently given in this article. I see that the article on pistol (a small gun) says: "The pistol originates in the 16th century, when early handguns were produced in Europe. The English word "pistol" was introduced in ca. 1570 from the Middle French pistolet (ca. 1550)." and the article on William Shakespeare says: "26 April 1564 (baptised) – 23 April 1616)" so quite new and "hip" in Shakespeare's lifetime but perhaps an odd choice of name for an character from a much earlier time. The origin, "whistle"?