1847 US Haston gun/pistle

This gun/pistol was passed down to me by my deceased relative.  I have no idea who it belonged to, or what the purchase price was.  Its barrel is made from metal and its shaft/handle is wooden with brass trimming.  It is very rustic.  This gun  was used with gun powder apparently.  The trigger is pulled back manually.  It has two "H" etching/engravings.  On the right side shaft of the gun, has US HASTON engraved, as well as "MIDDTN CONN 1847" engraved on the handle.