M4 corridor M4 corridor The M4 corridor is an area in the United Kingdom adjacent to the M4 motorway, which runs from London to South Wales. It is a major high-technology hub. Important cities and towns linked by the M4 include (from east to west) London, Slough, Bracknell, Maidenhead, Reading, Newbury, Swindon, Bath, Bristol, Newport, Cardiff, and Swansea. The area is also served by the Great Western Main Line, including the South Wales Main Line, and London Heathrow Airport. Technology companies with major operations located in the area include Amazon, Citrix Systems, Dell, Alcatel-Lucent, Huawei, Lexmark, LG, Microsoft, Novell, Nvidia, O2, Panasonic,
M4 carbine producing an "M4" in all but name. The M4 falls under restrictions of Title II of the National Firearms Act. The 14.5 inch barrel makes the M4 a Short Barrel Rifle (SBR) and select fire capability (semi-automatic and full automatic or burst-automatic) makes the M4 a machine gun. Civilian replicas of the M4 typically have 16 inch barrels (or standard 14.5 inch M4 barrels with permanently attached flash suppressors with a total length of 16 inches) and are semi-automatic-only to meet the legal definition of a rifle under the Gun Control Act. Civilian-legal M4s are also popular with police as