An SBR, or Short Barrel Rifle, is any rifle with a barrel less than 16″ in length. They are lighter and more maneuverable than longer barreled rifles, making them ideal for CQB. However, they are subject to the National Firearms Act (NFA), and require a tax stamp to legally own. The tax stamp itself costs $200, but the paperwork processing can take several months. They are a great type of weapon, but require a little extra money and patience to acquire. Alternatively you can look at AR Pistols.
Synonyms:
short barrel rifle