I dont dare try to complete the palace with no ammo!
The best place to go is Bricklane markets. over and over open the dumpsters and case behind the door. then go back where the man-hole is and open the door to bricklane flats where the apartment is? and hit those two dumpsters and zoMbi'es usually have ammo on them aswell. do that over and over as you keep going back to the safe house to store it in then gang box till you fill it up then go raise some HELL!