Dan: As you wish. If I were to devise an anti-zombie strategy, I would focus on choosing weapons for long-range, mid-range and short-range.
Long-range: Something with good distance, but uses easily acquired ammo (available at your local, abandoned Walmart). I’m gonna recommend the Remington 700 in 7.62mm NATO/.308 Winchester with an off-the-shelf Leupold telescopic sight.
Mid-range: Something will full-auto capabilities, also easily acquired from your local National Guard armory. Either the M16 or the M4, with a 4x or ACOG sight setup, if available.
Short-range: Something with tremendous stopping power, but able to be grabbed from any cop car anywhere in the US: 12ga pump gun, either Mossberg 590 or Remington 870P. I’d also go for a sidearm using .45ACP or .40S&W.