"This is why i keep more .22lr stocked than there are actual people living in the area around me. It's cheap and im a bit of a packrat so its a win win. 100 zombies wouldn't really be a problem if i was in my house. I can burn through 100 rounds of .22 at the range keeping it on a 6"x6"(head sized) target at 100yd like its nothing. Id go up on the roof and play my own version of sniper celebrity squares (like in the new dawn of the dead) for a few hours. There would be no rush since im on the roof and can take my time on each shot and the shots probably wouldnt be any farther than 50yd since they'd be packed in trying to get to the house. Id start at the back and work my way closer so 1. Id be making the longest shots before the barrel heats up and shots start to wander and 2. the bodies wouldn't pile up at the base of the house making a ramp to the roof.

If i was outside my home, foraging and whatnot, id probably have my AR-15 with me with 8 mags(240 rounds). If they are runners im probably boned and just gonna shoot as many as i can before they run me down. Or id just bolt and try to get home or look for a narrow area where i can engage the smallest number possible at one time. But even then id probably be overrun as soon as i had to reload. If they were walkers id pick a direction (probably towards home if possible) and start clearing my way out that way calmly keeping a brisk pace and picking my shots.

I think the key to getting out of this situation, apart from being smart and not letting it happen in the first place, is to stay calm and remember that you're smarter and faster than they are. Unless they're runners, in that case you're just boned so bend over and kiss your butt goodbye"