Chapter 10

Prepare to Fire

Prefire checks of the HMMWV weapon systems are important crew tasks. A prefire check must be made on the HMMWV weapon systems to eliminate all deficiencies associated with cleaning, maintenance, and functioning, and to make sure the weapon is safe to operate. A postfire check must be made after firing the weapon system, to detect any maintenance problems.

Prefire Checklist

The following prefire checklist is used for the weapon systems of the HMMWV, along with the appropriate operator’s manuals: M60 7.62-mm machine gun (TM 9-1005-224-10), M240B 7.62-mm machine gun (TM 9-1005-313-10), M2 HB caliber .50 machine gun (TM 9-1005-213-10), MK 19 40-mm grenade launcher machine gun (TM 9-1010-230-10), and TOW weapon system (FM 23-34).

PREFIRE CHECKLIST
Ammunition
  • Check all ammunition against TB 9-1300-385.
  • Inspect the link alignment.
  • Check for long or short rounds.
  • Check the cleanliness. (Report and turn in any corroded or damaged rounds.)
M60/M240B
Machine Gun
  • Make sure the machine gun is cleaned and lubricated IAW TM 9-1005-224-10 (M60) or TM 9-1005-313-10 (M240B).
  • Make sure the machine gun is installed and secured to the mount.
  • Make sure the machine gun is clear of ammunition.
  • Make sure the bore is wiped dry.
  • Conduct a function check of the machine gun.
M2 HB .50 Caliber
Machine Gun
  • Make sure the M2 HB machine gun is cleaned and lubricated IAW TM 9-1005-213-10.
  • Make sure the M2 HB machine gun is secured to the mount.
  • Make sure the headspace and timing are set.
  • Make sure the bore is wiped dry.
  • Conduct a function check of the M2 HB machine gun.
MK 19 40-mm
Grenade Launcher
Machine Gun
  • Make sure the MK 19 machine gun is cleaned IAW TM 9-1010-230-10.
  • Make sure the MK 19 machine gun is secured to the mount.
  • Make sure the bore is wiped dry.
  • Conduct a function check of the MK 19 machine gun.
TOW Weapon
System
  • Conduct the following missile checks:

    • - Check the outside for soil, dirt, grease, dents, gouges, punctures, and cracks.
    - Make sure the humidity indicator is blue.
    - Make sure the electrical connector dust cover is present.
    - Make sure the forward handling ring and quick-release clamp are present and secured.
    - Make sure the indexing lugs are not damaged.

  • Launcher checks:

    • - Inspect the assembled TOW launcher for obvious damage.
    - Conduct a system self-test (to include collimation) to determine if the launcher will function properly (correct or report any malfunctions). (Refer to FM 23-34 for boresighting and collimation procedures.)
    - Check DA Form 2408-4 (Weapon Record Data) to make sure the number of rounds fired is recorded.