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