http://www.sikhsangat.com/index.php?/topic/55713-the-word-pistol-is-siri-sarabloh-granth/
According to some people Sarbloh Granth Sahib is not written by Dasmesh Pita as it has word pistol in it.
But pistol existed during Guru Sahib Jee's time too.
A 17th century pistol can be seen at Maharaja Ranjit Singh War Museum in Ludhiana.
This museum is located on the road from Ludhiana to Phillaur.