 The trials conducted by the NII VVS included engagements between the Tu @-@ 12 and the Soviet MiG @-@ 9 and Yak @-@ 23 jet fighters which were very useful in evaluating the offensive armament of the fighters , the defensive armament of the bomber and the proper tactics involved for both types of aircraft . The tests demonstrated the inferiority of the current 12 @.@ 7 mm ( 0 @.@ 50 in ) armament and meant that every Soviet bomber henceforth would have a defensive armament using power @-@ operated turrets that carried guns 20 mm or larger . 
