The B-17 could carry 17,600 lbs of ord, but had to use external racks to carry anything more than 9,600, and the range was severely limited. Max internal bomb load for the G model was 9,600 lbs, but again rage suffered. The max load out over Germany was about 4,000 lbs.
Some normal operational max bomb loads, and rage at typical loads of notable WWII bombers:
B-17E:
Empty Weight: 33,280lb
Loaded weight: 53,000lb
Max Bomb Load: 4,000lb
Range: 1100 miles with 4,000lb
B-17F:
Empty Weight: 34,000lb
Loaded weight: 65,500lb
Max Bomb Load: 8,000lb
Range: 1,250 miles with 6,000lb
B-17G:
Empty Weight: 38,000lb
Loaded weight: 65,500lb
Max Bomb Load: 9,600lb
Range: 1200 miles with 6,000lb
B-24D:
Empty Weight: 32,605lb
Loaded weight: 71,200lb
Max Bomb Load: 12,000lb
Range: 1400 miles with 8,000lb
B-24J:
Empty Weight: 38,000lb
Loaded weight: 71,200lb
Max Bomb Load: 12,800lb
Range: 1540 miles with 8,000lb
B-29:
Empty Weight: 71,360lb
Loaded weight: 138,,000lb
Max Bomb Load: 20,000lb
Range: 1950 miles with 20,000lb
Halifax Mk.I:
Empty Weight: 33,860lb
Loaded weight: 55,000lb
Max Bomb Load: 13,000lb
Range: 980 miles with 13,000lb
Halifax Mk.III
Empty Weight: 39,000lb
Loaded weight: 65,000lb
Max Bomb Load: 13,000lb
Range: 1260 miles with 13,000lb
Lancaster B.I:
Empty Weight: 41,000lb
Loaded weight: 72,000lb
Max Bomb Load: 14,000lb
Range: 1040 miles with 12,000lb
Lancaster B.III:
Empty Weight: 41,500lb
Loaded weight: 72,000lb
Max Bomb Load: 14,000lb
Range: 1040 miles with 14,000lb
Lancaster B.I (Special):
Empty Weight: 36,000lb
Loaded weight: 72,000lb
Max Bomb Load: 20,000lb - Grand Slam
Range: 660 miles with 20,000lb
Heinkel He 111H:
Empty Weight: 17,000lb
Loaded weight: 30,8650lb
Max Bomb Load: 7,165lb
Range: 910 miles with 6,000lb
Heinkel He 177A-5:
Empty Weight: 37,038lb
Loaded weight: 68,343lb
Max Bomb Load: 13,225lb
Range: 1200 miles with 11,000lb