Service of the piece : 155-MM gun M2 : truck-drawn and tractor-drawn - USA War Department Field Manual, FM 6-90 Service of the piece : 155-mm gun M 1 - USA Field Artillery Field Manual, FM 6-90 Firing Tables for Gun 155 mm. M1 and M1A1. Firing. Shell H.E. M101. Shell Chemical M104. - USA Voorschrift Firing Tables 155-S-2