SURFREAK'S GUIDE TO ZOMBIE PANIC! (i only got Half Life 1 version, but they are similar enough for me to make this, you will learn from it regardless)
.45: The top weapon in my book. 7 shots, maximum of 70 bullets, and one heck of a good gun. Most people think that the pistol should only be used as a last ditch, medium range gun. I can agree, it cant hit anything beyond 20-30 feet in front of you, at which case you must use magnum.
Need for headshots is high, because it takes maybe 4 clips from this without headshots. Which means, this here is false:
Magnum: I love this gun. 6 shots, 36 maximum. Headshots are the reason why i love it. It takes down a zombie in one, nice, good shot. Its only good at medium-long range, because at close range its rate of fire hurts it.
Need for headshots is not to high, because 3 shots to the torso will take out a zombie.
M4 Carbine: This gun is hogged by pros, and is rare on every map except for zp_investigation. Its the equivalent of a .45 with 30/200 ammunition. If you get your hands on it, CONSERVE AMMO!!!! Even for me, this gun uses ammo fast.
Its good at medium range, so use it with a pistol for good effect.
Need for headshots is low.
Remington Pump-Action: This is by far the most common gun. My very first game was also my very first non-.45 gun. Being powerful with knockback, its good on zp_blocky's platforms due to knockback and ammo commonarity(is that a word?)
Need for headshots is non-existant, unless you are VERY DESPERATE.
Dynamite: Its not red, but its dynamite. Use it on zp_touchdown as you will need it. ONLY USE IT IF YOU HAVE MORE THAN ONE ZOMBIE ON YOUR TAIL, OR ITS A WASTE.
C4: Use it in almost any situation you find useful. Rare.
I hope you enjoyed the first stage of my guide to ZP.