Don't forget the gun.
Don't expect the armorer to be taking care of your unit's M3Ps. Usually, that's the Avenger crews' jobs. At least monthly, get your M3Ps out of the arms room and give them a good PMCS. Look for corrosion and signs the lube is drying up. Clean and lube the gun if necessary.
THE TWO MOST COMMON MISTAKES WHEN IT COMES TO CLEANING AND LUBING THE M3P ARE USING THE WRONG LUBRICANT AND PUTTING ON THE WRONG AMOUNT.
TW-25B, NSN 9150-01-439-0859, is the only lube to use on the gun. CLP is not strong enough to stand up to the heat the M3P produces during firing. (The elastic cradle, though, is lubed with LSA, not TW-25B.)
It the M3P is just going to sit in the arms room, give all parts a heavy lube. It's a different story for firing, though. Parts take different amounts of: lube then. See the chart on the next page for what parts get what lube.
Use this guide for how much lube to use and how to apply it:
* Light--white grease is slightly visible, Use a small brush or cleaning patch, They're part of the Avenger BII.
* Moderate--grease is visible. Use a brush of patch.
* Heavy--grease is plentiful. Use a large brush.
Remember to keep TW-25B off the face of the bolt and out of the inside of the barrel. Lube on the bolt face leads to carbon buildup. Lube can damage the barrel liner. Use RBC to clean inside and outside the barrel.
Cleaning While Mounted
The barrel extension can become sticky and gritty during firing, which makes it difficult for the bolt to move. But it's no problem to clean the extension while the gun is mounted:
Let the gun cool enough so it's sale to touch. Follow the steps for reloading until you reach the point where the cover is up. Make sure the ARM switch is set to SAFE and the bolt is locked to the rear.
Use a clean rag wrapped around a stick to clean inside the barrel extension, especially along the inner walls. Be very careful--the barrel grooves can be razor sharp.
If the extension is sticky or gritty, clean it with a rag. Then use a small brush to put on a moderate coat of TW-25B. After lubing, cycle the gun to spread the lube.
Check the extension after ever 1,250 rounds fired to see it more cleaning is needed.
If the M3P loses headspace during firing, the gun jams and the bolt and barrel may be damaged. And ir the barrel locking spring is weak, the gun loses headspace.
What weakens the spring is letting it ride on the barrel as you screw or unscrew the barrel. Keep the spring strong by holding the spring up slightly with a screwdriver or something similar as you turn the barrel.
Once the barrel is locked in, try to turn it. If there's any play, the locking spring needs to be replaced. Don't tire the gun. It's not safe.
Rate of Fire
The rate of tire should be 950 to 1,100 rounds per minute. If it's not, you'll have feeding problems. Check the rate of tire on the control display terminal (CDT). If it's wrong, reset it like it says in Para 4-7e in TM 9-1425-433-10. For more info on taking care of the M3P, see Steps 2-10 in Table 2-1 and Chapter 4 in the -10.
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|Title Annotation:||Avenger Missile System ...|
|Publication:||PS, the Preventive Maintenance Monthly|
|Date:||Jan 1, 2004|
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