Summary of the Weapon Stats

esert Eagle Bullet cost double of Beretta M9, but deals +31% extra damage. Not worth?
Steyr TMP is the fastest weapon, deals half damage of AK47 but bullet is almost half too. Useful for mass.
M14 aka Sniper Rifle is the slowest weapon, but deals the highest damage. Not good against mass zombies.
AK47 is the all-round weapon, deals good amount of damage and moderate cost. Good weapon choice.
However, M4 is the best weapon choice since the shooting is stable but cost a little more than AK47.