Green’s Dictionary of Slang

dotty n.

also dot, dot-dot, dots

(UK und.) a shotgun and its cartridges.

CPS Thames & Chiltern Online 4 Mar. [Internet] Text messages were recovered from Reid's Blackberry phone. One read: ‘Got a couple of burners (guns) for sale.’ Another referred to "‘10 bore dotties’ - slang for shotgun cartridges.
410 ‘Four Door Coming’ [lyrics] 2 hands on a stick, man I’m tryna catch me a body / Niggas know juice garn spill, if you see me riding with Dotty.
1011 ‘Next Up?’ [lyrics] My bros ain't down for the stunting / Digga D grab that dots and shoot.
[UK]Unknown T ‘Mad about Bars’ [lyrics] Had a dot-dot up in the cab, got Polkas in bags.