 The T30 's main armament was a short <unk> 3 @.@ 0 in ( 75 mm ) pack howitzer . The 75 mm Pack Howitzer <unk> as mounted could depress nine degrees , elevate 50 degrees , and traverse 22 @.@ 5 degrees to each side . The vehicle had stowage for sixty rounds of 75 mm ammunition and , although it was not designed for anti @-@ tank use , it had a high explosive anti @-@ tank ( <unk> ) shell that could penetrate 3 in ( 76 mm ) of armor . The gun shield had 0 @.@ 375 in ( 9 @.@ 5 mm ) thick armor , designed to stop a <unk> cal ( 7 @.@ 62 mm ) bullet from 250 yards ( 230 m ) away . 
