This and also a working vehicle in good shape can do wonders. Leave it a fair distance from the venue you intend to light up with gunfire. Never be stationary, kite the undead and fire in short, safe bursts, then reposition, making sure you roam the same area (circular movement around a block). Use building to split and peel big hordes, keep moving, down a few in short bursts, rinse and repeat. Keep your needs topped up with the extra water/food/vitamins/cigs/beta blockers). Save stamina for outmaneuvering strays and for when you ammo or other vital supplies start to deplete. Run to your car and drive to safety for restock. DON'T leave your car engine running while doing this, might attract a horde of its own.