Give carbon the boot.

Crewmen, keeping the muzzle brake and bore evacuator free of carbon is one secret to straight shooting with your M109-series SP howitzer.

Each time the cannon is fired, a little carbon builds up inside. Wait too long for a cleaning and enough accumulates to freeze the two parts in place. They become almost impossible to remove.

Avoid that sticky problem by removing, cleaning, and greasing the muzzle brake quarterly or after every 300 rounds fired. The bore evacuator should be cleaned after firing and monthly if not fired.

1. Eyeball the muzzle brake for cracks, lf you spot one longer than one inch, you need a new muzzle brake.

2. Remove the muzzle brake and bore evacuator following the instructions starting on Page 3-53 of TM 9-2350-311-10 and Page 3-97 of TM 9-2350-314-10. The muzzle brake weighs about 350 pounds and the bore evacuator is no lightweight, either, so always use the proper lifting equipment.

3. Lay the parts on a clean dropcloth to prevent contamination by dirt and sand.

4. Thoroughly spray all the carbon-coated surfaces of the muzzle brake and bore evacuator with CLP, NSN 9150-01-054-6453. Let the CLP soak for a few minutes, then scrub until all the carbon is removed. Use the bore evacuator brush from the cleaning and preservative artillery kit, NSN 1025-01-196-2172, and some clean rags. You can also substitute bore evacuator brush, NSN 1005-00-903-1296, for scrubbing.

5. Lightly coat the muzzle brake threads with general purpose grease, NSN 9150-00-754-2595. Then, lightly lube the inside, valve balls, valve ring and all unpainted surfaces on the bore evacuator.

6. Reassemble the muzzle brake and bore evacuator following the instructions in the operator's manuals.