Nuthin' But A G Thang The Chronic Dr. Dre

pimpin' hoes and clockin' a grip like my name was Dolemite

I am selling women on the streets and carrying a gun with me as if I were the 1970s movie character Dolemite (a sort of low-budget version of Shaft)
With all due respect, 'clockin a grip' doesn't have anything to do with guns. 'A grip' is slang for 'a lot.' So, what he's saying here is that he's making (clockin') a lot of money as a pimp. The Dolemite bit is pretty spot on though.