TM-9-2350-311-10 M109 Operator's Manual for M109A2, M109A3, M109A4 and M109A5 Download
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TM 9-2350-311-10 2-12 PREPARATION FOR FIRING — CONTINUED 2-12.3 Standard Angle Method — Continued a. Determining the Standard Angle — Continued NOTE • The scribe line at the junction of the muzzle brake and cannon tube verifies that the muzzle brake has not shifted. Therefore, the standard angle should remain unchanged. • Scribe lines must be alined when installing the muzzle brake after maintenance. If the scribe lines don’t match, fire control alinement tests must be performed, new scribe lines made, and new standard angle determined. 4 Scribe a line at the junction of the muzzle brake (4) and the cannon tube (5). NOTE • Alining the scribe lines on cross-level mechanism knob and the cross-level mechanism and the scribe lines on pitch level knob and bracket serves as the coarse alinement indices for these two mounts. • The marks placed on the Ml 45/M145A1 telescope mount cross-level knob and pitch level knob serve as the fine indices for conducting the standard angle test. 5 Rotate the M145/M145A1 telescope mount (6) cross-level mechanism knob (7) until scribe lines on cross-level mechanism knob and cross-level mechanism (8) aline. 6 Rotate the M145IM145A1 telescope mount (6) pitch level knob (9) until scribe lines on pitch level knob and bracket (10) aline. 2-194