Below is a chart of potential items that may cause your rifle to fail. Next to it are the symptoms and fixes to correct the problem.  Please read the cart carefully as it will make a difference.

 

Problem	Check for	Procedure
Bold wont Unlock	1. Dirty or burred bolt 2. Damaged Gas tube or piston	1. Clean or replace 2. Repair or replace
Bolt wont Lock	1. Fouling in locking lugs 2. Frozen extractor 3. Recoil spring is not moving freely 4. Bolt is not moving freely. 5. Gas piston misaligned. 6. Loose or damaged piston. 7. Dent in gas tube	1. Clean & lubricate lugs. 2. Remove clean extractor. 3. Remove clean & lubricate. 4. Remove clean & lubricate. 5. Check alignment 6. Tighten or replace 7. Repair or replace
Double feeding	1. Defective magazine.	Replace
Firearm wont cock selector doesn't work properly.	Worn broken or missing parts.	Check parts, Replace
Firearm continues to fire after release of trigger	1. Dirt in trigger/sear 2. Broken sear/trigger 3. Weak sear/trigger spring 4. Firing pin dirty or too long	1. Clean mechanism 2. Replace 3. Replace spring 4. Clean or replace
Firearm wont fire	1. Safety in safe position 2. Firing pin is broken 3. Too much dirt/oil in firing pin recess 4. Poor ammo 5. Weak or broken hammer or spring 6. Weak or broken sear/sear spring 7. Bolt isn't locking	1. Place in fire position 3. Replace 4. Wipe/Clean 5. Remove/discard 6. Replace 7. Replace 8. Clean dirty parts
Round won't chamber	1. Dirty or corroded ammo 2. Damaged ammo 3. Fouling in chamber	1. Clean ammo 2. Replace 3. Clean chamber
Rounds won't eject	1. Broken ejector 2. Frozen ejector 3. Bad ejector spring	1. Replace 2. Clean/lubricate 3. Replace
Rounds won't extract	1. Broken extractor or bad extractor spring 2. Dirty/corroded ammo 3. Carbon/fouling in chamber or extractor lip 4. Dirty/fouling recoil spring	1. Replace 2. Remove (use extreme caution with live round) 3. Clean chamber & lip 4. Clean/replace
Rounds won't feed	1. Dirty or corroded ammo 2. Low powered ammo 3. Defective magazine 4. Dirt in magazine 5. Too many rounds in magazine 6. Insufficient gas to cycle action fully 7. Magazine not seated 8. Broken magazine catch	1. Clean off ammo 2. Use different ammo 3. Replace 4. Clean & lubricate 5. Remove several rounds 6. Clean out gas port 7. Reseat or replace 8. Broken magazine catch
Selector level binds	Fouling/lack or lubrication	Lubricate/clean
Short Recoil	1. Poor ammo 2. Fouling in gas port 3. Damaged piston 4. Dent in gas tube	1. Replace 2. Clean gas port 3. Repair/replace 4. Repair/replace