Location
San Diego, CA
The United States was hit by an EMP attack. You and your four /k/ommando friends have holed up in a newly built medical office building (mainly due to it's new construction and it's relatively long fields of fire [200-400 yds]).
All of you can hit a man sized target with reliability at distances of 400yds.
All of you are of average body mass, none overweight, but none very lean.
All of you are over 18 years old, but under 40.
The power grid is down, and it is unknown when it will return.
Weapons and ammunition
You have a mixmatch collection of arms, a mosin, an SKS, an AR-15, and a scoped fudd rifle, with a ruger .22 rifle for varmits. For side arms, one of you has a Glock 17, one a Walther P99, and one a Ruger MKIII .22 pistol.
For ammunition, your group has half a spam can (~230 rounds) of 54r, around 250 rounds of 7.62x39, 900 rounds of .22, and 450 rounds of .223. An additional 300 rounds of 9mm is had.
Threats
As you are in an urban area, you will most likely be fighting against unorganized raiders looking for easy prey. Once you make yourself known, some may unite to try to take you down.
Food and water
You have 8 gallons of water per person, not counting what's in the building.
There is a creek 1km north, down a government road. It passes under I-15, so you can be damn sure there will be people there. You are unsure of their hostility, but due to the fact that it's the only water source for miles, you assume the worst.
For food, you have 4 days worth per person. One of you has 5-6 50lb buckets of beans and rice for food, that need to be brought up to the building.
*NOTE: this is a desert region, so natural food and water sources will not be plentiful.
Now that the details are out of the way, let's get started.