Guess with today's military, is it still such a sure thing that they'd all be wiped out by zombies? Seems to be par for the course in most zombie stories told. I mean the first few skirmishes, I could see some heavy losses til they figured the trick to taking them down, but would the worlds military fire power really go down so quickly? Cause if not, a military base still may not be a bad choice to go for shelter.
Works in theory. But there's a reason that the world's military are typically wiped out during the zombie pandemic in these Zombie Apocalypse stories (aside from the more interesting storylines of ordinary people being called upon to do extraordinary things to survive).
1) A zombie pandemic would take the world be surprise. The first few attacks would be written off as "isolated incidents". After that, the walkers would be seen as people who are "sick" and can be "cured" (much as Hershel saw them in the beginning of S2). They would be contained and studied. Likely it would be believed that they contracted some newly mutated form of rabies. The first people to figure out that these "rabid people" are undead would likely be written off as crazy. Honestly, how would YOU react if someone came up to you and said that the dead were rising up and eating the living? You probably think he's been smoking too much weed while watching Romero movies. By the time the authorities realize the truth, it'll be too late. Likely their quarantined "patients" will break loose and tear into everyone they see, increasing their numbers astronomically.
2) Soldiers are trained to aim for the area most likely to incapacitate/kill their target. That means the torso, everything from waist to neck. Stomach, liver, kidney, heart, or lungs. Shoot a man in any one of those and even if you don't kill him, you'll take him out of the fight. They generally don't go for head shots as it's a harder target to hit, and if they miss they could give away their position. This has been drilled into them until it becomes second nature. Even when they understand what they're dealing with and how to stop them, the soldier's instincts will always lead him back to his training.
3) Even if the soldiers were to be aiming specifically for the zombies' heads with every shot, soldiers will tire and have to stop to reload, while the zombies will just keep on coming. If the horde is large enough, the soldiers could run out of bullets before the horde runs out of zombies.
4) Early in the pandemic, many recently bitten victims would seek medical help at military bases. That would put the enemy behind the soldiers' defensive position before the horde even attacks. The base could end up being overrun not from without, but from within.
Anyway, a military base might be a good place to scavenge for supplies after the fact, assuming the walkers aren't just milling about there. But I don't think you'll want to be there when the s**t hits the fan.