The Ruger 10-22 is a semi-automatic rifle famous for being cheap, reliable, accurate and for having a myriad of aftermarket modifications available. Furthermore, the .22 LR catridges it uses is easily obtainable, cheap and many rounds can be carried around. It is an immensely popular weapon, boasting some of the highest sales for .22 caliber weaponry.
However, the low power of the .22 rounds can be both an advantage and disadvantage. The low muzzle velocity means that recoil is kept to a minimum, making it suitable for inexperienced people who are not used to the recoil of other higher powered catridges, though it also limits range and stopping power.
Because of the above qualities, it is very valuable, both as a training weapon and as a zombie killing tool.
The round has endured relentless speculation concerning the cranial penetration power, but as any expert will tell, the gun is less important than the training. This gun is ideal for training recruits and basic duty.
Although the .22 LR catridge is low powered, upon entering a zombie's skull, it does not have enough velocity to leave the skull, so the bullet bounces around inside destroying the brain matter. This easily makes the 10/22 a deadly weapon. Note that the .22 LR cartridge, while far less powerful than larger cartridges, is still dangerous; in fact, its deceptive "low-power" reputation can make it more dangerous because some shooters do not pay it the same respect as larger cartridges, and shoot it carelessly. It can easily kill or severely injure humans and larger animals.