It's a descendant of the archetypal firearms made in the 13th century, the original handgonnes. A small, portable cannon affixed to the end of a staff, they represent a nascent firearm, with a touchhole for ignition, a short bore, and a closed end where powder and ball were to be loaded. Some original handgonnes can be seen here.
The quality on my proto-Snubbie-from-Hell™ is evident:
Spear does some impressive smithing. And I think it's quite fitting that he begin what I can only assume will be a long and successful career as a gunsmith with the earliest form of firearm; truly, he begins at the beginning. Very zen. It's not every day you get to see one of the earliest forms of firearms, let alone hold one in your hand.
Last shot is the naughty end:
Yes, that is a .50". Dianne Feinstein would have you believe this could shoot down an airplane...
Of course, this had to be done:
All that's left is to
That is all.