A stock, also known as a shoulder stock, a buttstock, or simply a butt is a part of a rifle or other firearm, to which the barrel and firing mechanism are attached, that is held against one's shoulder when firing the gun. Stocks allow the shooter to firmly support the device and easily aim it. It also reduces weapon recoil by transmitting it into the shooter's body.
Stocks are featured in every installment of the Battlefield series due to being default attachments for most weapons.
A variety of Stocks appears in Battlefield Play4Free .
— In-Game Description
The Stock is a weapon attachment featured in Battlefield Hardline for several weapons that do not have a buttstock by default, including the MP5K, MPX MAC-10, SCAR-H, and HK51, and M1. The FN FAL can also equip the attachment, but is uniquely given synthetic furniture instead of a buttstock, as it already has one by default. The stock reduces a weapon's spread increase by 50% once equipped, much like a stubby/potato grip, increasing accuracy with automatic fire.