Proper PMCS is important. That’s true even when it comes to the M192 machine gun mount’s traverse and elevation (T&E) mechanism.
Some of you may have reported that the M192’s T&E mechanism is failing to hold its elevation while the weapon is mounted or even while firing! That’s because the T&E’s elevation can slip or creep if the locking plates are worn.
A worn locking plate can touch the actuator, which leads to slippage. And that’s not what you want.
But this problem can go away if inspections are done during PMCS to identify worn locking plates or a bad T&E.
Operators, do these four steps to check your T&E for slippage during PMCS:
- Place the M192 into operation following the guidance in TM 9-1005-344-10 (Feb 07).
- Mount either an M249 or M240 machine gun.
- Elevate or depress the weapon so it’s level with the ground.
- Stand behind the weapon. Then push downward with both hands on the buttstock, using moderate force.
There are two possible results.
1. If the buttstock depresses (muzzle raises), tell the armorer.
2. If the buttstock doesn’t depress, the T&E is good to go.
Armorers, do these four checks when you get a report of T&E slippage or creeping:
- Remove the elevation cover following instructions in TM 9-1005-245-13&P (Jan 06).
- Place the shoulder screw back in the elevation housing.
- Using a .015 feeler gage, check the wear of the elevation locking plate by inserting the feeler gage between the actuator and locking plate.
Where to insert the feeler gage
- If the feeler gage can’t be inserted between the actuator and locking plate, replace the locking plate as a set. Also, note that when inserting the feeler gage, some resistance is allowed.
These PMCS changes will be added when the new TM is released. Until then, include these steps in your routine BEFORE and AFTER PMCS checks.