The B-17’s design underwent eight major changes during the production process, accumulating in the B-17G version, differing from its previous version by adding a two-gun “chin” turret. 0.50-inch (12.7 mm) M2 Browning machine under the nose of the aircraft. Trump More Jobs Obama No Jobs Clinton Blow Job shirt. This allowed the B-17’s main weakness to be limited when attacked directly. After investigating the downed B-17 and B-24, Luftwaffe officials discovered that at least 20 shots of 20 mm (0.79 inch) MG 151 shells had to be fired. it was possible to shoot down a B-17. The average pilot can only hit bombers with about 2% of the bullets fired, so to achieve 20 hits, an average pilot must aim at about a thousand bullets 20 mm (0.79 inch) cannon on a bomber.
