It takes zombies a long time to run 400 m. By the time they get to your position, you'll have already fired a few rounds and melted back into the landscape without aggroing. AS50 is a great loner gun, you've got a longer reach than anybody else and even in close quarters a no-scope with a semi-auto one-shot-kill isn't that unplausible. I've bumped into a few players at close range and managed hit them with a .50, not ideal but it still chews em up. One thing to note as a loner... the scope is a handicap in the dark, you'll find yourself outgunned with only your .45 at night. Carry another primary/have a camp to re-equip/or plan accordingly.
