will smith - getting jiggy wit it.
hah but seriously? I can't think of a song with just raw gunshots but a few 'gangsta' ones are:
AOD - (any of their songs)
D12 - keep talkin, pimp like me, rap game
eazy e - real motherphuckin g's
freddie foxx
ice cube - what can i do
ja rule - how many wanna (surprisingly enough, he was alot harder before rapping with ashanti and that shit)
mack 10 - west side foe life
memphis bleek, trick daddy, ti - round here
nwa - chin check, gangsta gangsta,
westside connection - bow down, killa cali, king of the hill