Bring back the Thompson and B.A.R. for urban assault/building clearing! 
 Then your squad can have long range weapons specialist to use the less effective far range weapons to pick off the runners. Tommy gun and B.A.R are 2 of the most deadly close in combination weapons you can find for in close fighting other than a shotgun IMO. 
Isn't the BAR like 20 lbs? With a complicated-to-reload 20 round magazine?
According to Wiki:
Type    Automatic rifle
Place of origin    Flag of the United States United States
Service history
In service    1917–1960s (U.S.)
Used by    United States
Wars    World War I, World War II, Korean War, Vietnam War (limited), Palestinian Civil War
Production history
Designed    1917
Produced    1917–1940s
Number built    See design
Variants    M1918A1, M1918A2, M1922
Specifications
Weight    7.2–8.8 kg (16–19 lb) empty
Length    1,214 mm (47.8 in)
Barrel length    610 mm (24 in)
Cartridge    .30-06 Springfield (7.62x63mm)
Action    Gas-operated, open bolt
Rate of fire    300–650 rounds/min
Muzzle velocity    805 m/s (2,640 ft/s)
Effective range    548 m (600 yd)
Feed system    20-round detachable box magazine
VS. the AK (this is under the Wikipedia article for AK47... a modern variant like the AKM or AK103 would be lighter and more accurate with a higher rate of fire, IIRC)
Type    Assault rifle
Place of origin    Flag of the Soviet Union Soviet Union
Service history
In service    1949–present
Used by    Warsaw Pact, Post-Soviet states, many others
Production history
Designer    Mikhail Kalashnikov
Designed    1944-1946
Manufacturer    Izhmash
Variants    See Variants
Specifications
Weight    4.3 kg (9.5 lb) with empty magazine
Length    870 mm (34.3 in) fixed wooden stock
875 mm (34.4 in) folding stock extended
645 mm (25.4 in) stock folded
Barrel length    415 mm (16.3 in)
Cartridge    7.62x39mm M43
Action    Gas-operated, rotating bolt
Rate of fire    600 rounds/min
Muzzle velocity    715 m/s (2,346 ft/s)
Effective range    100-800 sight adjustments m
Feed system    30-round detachable box magazine, also compatible with 40-round box or 75-round drum magazines from the RPK
Sights    Adjustable iron sights, 378 mm (14.9 in) sight radius