I think for shot contace you cant go wrong with a short barrel 12 guage shotgun. but if im sitting up on my porch on the second floor shototing zombies id want a simple Ruger 10/22. a .22 its easy to shoot and with a scope can be extremely accurate. plus the ammo is light weight and sold in bulk.
I am a very adept at long range inguagements of zombies and also recon and obsevation but the wepone i am most profecent with id say is my Rimington 45 caliber with a 100X electronic scope and a 12 shot clip im in buissness but i carry a few other things thanks to my dads connections with the army I also own a berreta m9 pistol a combat knife a few illegal hand granades and last but not least a 5-pound C4 charge that will detonate when i press a switch thats my suicide charge well im gonna die any way might as well