SAFETY FUNDAMENTALS

Please familiarize yourself with this manual and the operation of your particular firearm. To ensure that you get the best performance and reliability from your new CMMG firearm, please read through all of the procedures listed in this manual before attempting to perform any of the described actions. If any part of this manual is unclear to you, please contact us before attempting the procedure.

All complete firearms and uppers are headspaced and test fired before shipping.

Clean your firearm before using it for the first time.

1. Always treat every firearm as if it is loaded.
2. Always keep the firearm pointed in a safe direction.
3. Always keep your finger off the trigger until ready to shoot.
4. Be aware of your target and what is beyond.
5. Always keep the firearm unloaded until ready to use.
6. Be sure the firearm is safe to operate.
7. Know how to use the firearm safely.
8. Use only the correct ammunition for the firearm.
9. Wear appropriate eye and ear protection.
10. Never use alcohol or drugs before or while shooting.
11. Store firearms so that they are not accessible to unauthorized persons.
12. Be aware that certain types of firearms and many shooting activities require additional safety precautions.

Failure to follow these rules can result in damage to property, injury, or death. Always follow these instructions and carefully read and refer to this manual before loading a firearm.

THIS IS NOT A SAFETY MANUAL.  If you need assistance with the safe handling of this or any firearm, please contact a certified firearms instructor or school.

UNLOADING AND CLEARING YOUR FIREARM

1. Keep your rifle pointed in a safe direction for the duration of the procedure.
2. Place your selector on “SAFE”. You cannot select “SAFE” unless the hammer is cocked.
3. Depress the magazine catch button and remove the magazine.
4. Eject the chambered cartridge by retracting the charging handle until it stops. Let the ejected cartridge fall to the ground.
5. Lock the bolt open by depressing the bottom of the bolt catch. If you cannot manipulate the charging handle and the bolt catch at the same time, you can use an empty magazine, which will activate the bolt catch for you.
6. Push the charging handle forward until it clicks to re-latch the charging handle.
7. Inspect the chamber and receiver to ensure you have removed all cartridges from the action.

Your rifle is now unloaded and clear. It may now be loaded or prepped for transportation or storage.

LOADING YOUR FIREARM

Begin with a firearm that has been verified to be unloaded using the preceding directions.

1. Keep your firearm pointed in a safe direction for the duration of the procedure.
2. Load your magazine with the proper cartridges. Place cartridge between the magazines feed lips and push down to seat.
3. Using firm and steady pressure insert the loaded magazine into the magazine well until the magazine catch locks the magazine in place. Do not slam the magazine into position; it will damage your magazine and rifle. Pull the magazine down to verify that it is locked in place.
4. To chamber a cartridge, you may depress the bolt catch or retract the charging handle until the bolt is no longer being held by the bolt catch. Release the charging handle. Do not maintain control of the charging handle while chambering a cartridge; this will cause the rifle to miss feed.

FIRING YOUR FIREARM

The following is a description of the sequence for one complete firing cycle; beginning after a cartridge is chambered. Knowing the correct function of your rifle will help you with the diagnosis of any malfunctions or failures to fire. The trigger is pulled, releasing the hammer which strikes the firing pin. The firing pin impacts the primer in the chambered cartridge igniting the primer which ignites the powder. As the powder is burned it creates a high volume of gas, which propels the bullet down the bore of the barrel. The exhaust gas is also vented out of the bore through the barrel’s gas port, into the gas block and through the gas tube, and into the carrier key on the bolt carrier. The gas pushes the bolt carrier back unlocking your bolt from the barrel extension and allowing the bolt carrier to recoil completely. The underside of the carrier will push the hammer down where it is caught and held by the disconnector. The bolt will pull the spent cartridge out of the chamber and eject it from the firearm.

At full recoil, the carrier has compressed the action spring rearward in the upper receiver. The magazine will present a new cartridge, which will be stripped from the magazine by the bolt as the action spring pushes the bolt carrier group back into battery. The new cartridge is now chambered. The fire control group will reset once you have released the trigger allowing the disconnector to release the hammer and re-engage the trigger’s sear. The rifle is ready to be fired again or put on “SAFE” and unloaded.

1. Align your sights on your target.
2. Place the selector on “FIRE”; Your rifle is now ready to shoot.
3. Squeeze the trigger until the hammer is released.

DISASSEMBLY INSTRUCTIONS

Before disassembling your rifle please unload and clear your rifle as described in the unloading directions.

1. Reverify your rifle is unloaded and return the bolt and carrier into battery.
2. Partially push the rear takedown pin and the front pivot pin from the left so they are not captured by the detents that retain them in the receiver in the closed position. Use a plastic takedown pin punch if needed.
3. Pull the rear takedown pin the rest of the way to the right side of the lower receiver until it engages the detent that holds the pin in the open position.
4. Pivot the lower receiver away from the upper receiver.
5. Pull the front pivot pin the rest of the way to the right side of the lower receiver until it engages the detent that holds the pin in the open position.
6. The upper and lower receivers are now separated; set the upper receiver aside.
7. Pick the upper receiver up. Pull the charging handle all the way to the rear to push the action assembly out of the upper receiver. Place the upper receiver aside.
8. Remove the action assembly bumper by pushing it up from underneath the action assembly. Place this part aside.
9. Remove the backplate. Place the action assembly bolt-side first down on a flat surface and depress both springs by hand to take the tension off the backplate, which can now slide freely off the guide rods. Carefully remove springs from the guide rods.
10. Remove guide rods from the carrier assembly. Once the springs are removed, they should be free to slide forward out of the carrier key. This will also allow the anti-bounce weight to be removed from the carrier assembly.
11. Remove the firing pin retaining pin from the left side of the bolt carrier group.
    1. WARNING: If your BCG is marked stating that a Titanium Firing Pin is installed, only replace with a genuine CMMG titanium firing pin. Please contact customer service with questions.
12. Tilt bolt face up and remove the firing pin from the rear of the bolt carrier.
13. For DI firearms, push bolt into the carrier until it rotates and comes to a stop (in battery position). This will align the cam pin with a recess in the carrier key for removal. RDB firearms align the carrier key and the cam pin for removal without any additional steps. 
14. For DI firearms, turn the cam pin 90 degrees and lift it out from the bolt and carrier. For RDB firearms, use a flat head screwdriver to pull the head of the cam pin up towards the carrier key. Turn the carrier upside down and gently tap on a flat surface to remove the cam pin from the carrier and bolt.
15. Pull bolt forward out of the carrier. Set the carrier aside.
16. With a punch, remove the extractor pin from the bolt assembly. Slight pressure applied to the extractor will ease removal of the extractor pin.
17. Remove the extractor. The extractor spring and elastomer insert should be captured in the extractor; do not remove the spring and elastomer from the extractor.

Your rifle is now field stripped for cleaning.

Do not disassemble your firearm any further than described. Any maintenance that requires further disassembly should be performed by CMMG or a qualified gunsmith.

BASIC CARE AND MAINTENANCE

Proper maintenance will ensure you get the best performance from your firearm. High-quality cleaning products will ensure that you get your rifle clean quickly and without damage to your firearm. The Mil-Spec cleaning kit is great for field use, but a good set of cleaning tools and a one-piece cleaning rod will make your task easier at home. There are also many excellent cleaning products available to shooters today. We do not recommend any specific brand, so use what you like. Just make sure that it is safe to use on the parts you are cleaning.

UPPER MAINTENANCE

1. Use cleaning fluid on the bore and chamber, the gas tube, the upper receiver & barrel assembly, locking lugs, and all areas of powder fouling, corrosion, dirt, or dust.
2. Install the chamber brush on the cleaning rod, dip the brush in cleaning fluid and insert it into the chamber and locking lugs. Clean by pushing and twisting the cleaning rod.
3. Install the bore brush on the complete cleaning rod. Dip the brush in cleaning fluid. Run the rod through the chamber and flash suppressor or muzzle brake several times.
4. Take the bore brush off the rod and install a swab holder and a swab. Apply cleaning fluid to the swab; then run it through the chamber and out the flash suppressor (if applicable). To remove carbon build up, let the solvent sit, then wipe clean. Wipe the bore dry by running clean swabs all the way through from the chamber to the flash suppressor.
5. Once the patches come out dry they should be clean. If not repeat steps 3 and 4.
6. Use a worn out bore brush to clean the outside surface of the protruding gas tube. NOTE: Heat will discolor your gas tube, do not try to remove this discoloration.
7. Wipe the charging handle with a patch dipped in solvent; wipe off solvent with a dry cloth.
8. Inspect the upper assembly for any worn, broken, or damaged parts. Replace any faulty parts with quality replacement parts.
9. Lightly lubricate the bore and chamber, outer surface of the barrel, front sight or gas block, under the handguard, and the charging handle.
10. With a lubricated swab, run the rod from the receiver to the flash suppressor or muzzle brake. Do not over lubricate.
11. Lubricate the locking lugs.
12. Reassemble upper.

BOLT AND CARRIER MAINTENANCE

WARNING: Never interchange bolts between rifles.

NOTICE: If your BCG is marked stating that a Titanium Firing Pin is installed, only replace with a genuine CMMG titanium firing pin. Please contact customer service with questions.

1. Clean all parts and outer surfaces of the bolt carrier assembly with a swab saturated with cleaning fluid.
2. Clean the bolt carrier key with a worn bore brush dipped in cleaning fluid and dry with a pipe cleaner.
3. Remove carbon deposits and dirt from the locking lugs with a cleaning brush dipped in cleaning fluid.
4. Clean the areas behind the bolt rings and under the lip of the extractor.
5. Use a punch to press the ejector in repeatedly to remove accumulated brass shavings from the ejector hole and assure the ejector moves freely. Be careful not to damage the bolt with the punch.
6. Inspect the bolt assembly for cracks or fractures, especially in the cam pin hole area. Inspect the firing pin retaining pin for bends, breaks, or dents. Inspect the bolt cam pin for cracks or chips. Inspect the firing pin for bends, cracks, or a sharp, chipped, or blunted tip.
7. Lubricate the bolt carrier, bolt, cam pin, firing pin, and firing pin retaining pin. Be sure to coat the inner and outer surfaces and the cam pin area of the bolt carrier. Place one drop of lubricant inside the key. Flush the ejector with lubricant and cycle the plunger enough to ensure the ejector spring is well lubricated.
8. Reassemble bolt and carrier.

LOWER MAINTENANCE

1. Remove any dirt or debris from the trigger group with a cleaning brush and/or cotton swab dipped in cleaning fluid.
2. Remove powder fouling, corrosion, and dirt from the lower receiver with a cleaning brush and/or cotton swab dipped in cleaning fluid.
3. Examine the lower receiver assembly for any worn, broken, or damaged parts. Replace any faulty parts with quality replacement parts.
4. Lightly lubricate the lower receiver and the internal parts of the lower receiver assembly.
5. Reassemble the lower receiver.

REASSEMBLY INSTRUCTIONS

1. Insert extractor and spring assembly into bolt by pushing extractor assembly down and aligning the pivot hole in the extractor with the hole in bolt and insert extractor pin. If the spring comes loose, seat the large end of the spring in the extractor.
2. Stagger the bolt rings to prevent gas loss. Not required if equipped with one piece gas ring or on RDB firearm.
3. Slide bolt assembly into bolt carrier assembly with extractor claw on the carrier’s right side.
4. Align the bolt’s cam pin hole with the carrier's cam pin slot. Insert bolt cam pin and rotate it 90°.
5. Insert firing pin into the opening at the rear of the bolt carrier and seat. You may need to rotate the cam pin into alignment to allow the firing pin to seat.
   1. NOTE: If your BCG is marked stating that a Titanium Firing Pin is installed, only replace with a genuine CMMG titanium firing pin. Please contact customer service with questions.
6. Pull bolt assembly forward and replace firing pin retaining pin. When correctly installed the firing pin will not fall from the bolt carrier assembly and cannot be removed.
7. Place the anti-bounce weight in position on the carrier key and insert the guide rods from the front of the carrier assembly, ensuring that the anti-bounce weight is properly seated.
8. Place the front of the carrier key down against a flat surface and place action springs on the guide rods.
9. Depress the action springs on the guide rods to allow the backplate to slide onto the grooves on the back of the guide rods. If assembled properly, the springs will be retained. Ensure that the anti-bounce weight is in the correct position on the carrier key.
10. Insert the bumper from the top of the guide rods, pushing it into its mating position against the backplate. This completes the action assembly.
11. Pick up the upper receiver and place the action assembly into it, aligning the carrier key and carrier. This should slide freely forward and push the charging handle into the forward-most position.
12. The hammer must be cocked and the selector lever must be on SAFE before installing the upper receiver onto the lower receiver.
13. Align the pivot holes and push pivot pin in.
14. Pivot the lower receiver towards the upper receiver. When aligned, push in the takedown pin.
15. Perform the function check on your firearm.

FUNCTION CHECK

TO AVOID ACCIDENTAL FIRING, BE SURE MAGAZINE IS REMOVED AND CHAMBER IS EMPTY

1. Pull charging handle assembly to rear and release.
2. Place selector lever on SAFE. Squeeze trigger. Hammer should not fall.
3. Place selector lever on FIRE. Squeeze trigger. Hammer should fall.
4. Hold trigger to the rear. Cycle the action. Release trigger. You should hear a click as you release the trigger as the disconnector hands the hammer off to the trigger.
5. Squeeze trigger again. Hammer should fall.

If your rifle fails any of these tests check your assembly. If the rifle will not pass these checks and it has been assembled properly, contact CMMG or a qualified gunsmith for assistance.

HOW TO CHANGE THE CHARGING HANDLE TO THE LEFT SIDE

1. Pull the takedown pin from the right side of the DISSENT.
2. Pivot the upper open from lower.
3. Pull back on the side charger until the handle is in the most rearward position (this will cause the compact action to exit the rear of the upper).
4. Pull out on the side charger removing it from its carrier under the handguard.
5. Insert the left side charger into the carrier through the notch in the handguard.
6. Push the compact action assembly back into the upper.
7. Continue putting pressure on the compact action while closing the upper onto the lower.
8. Close the takedown pin.
9. Perform a function check.

HOW TO ADJUST THE GAS BLOCK (Direct Impingement MODELS ONLY)

Tools needed:

• 3/32nds hex wrench

1. Locate the adjustable gas screw on the gas block under the front of the handguard.
2. Using the hex wrench, turn the screw clockwise to restrict the flow of gas.
3. Using the hex wrench, turn the screw counter-clockwise to open the flow of gas.

• From the factory, the gas block is set to 7-9 clicks from closed.
• Fully open is approximately 16 clicks from closed.
• Each click is approximately 1/3 turn of the screw.

• When tuned properly, your ejection pattern should be ejecting at the 3 o’clock to 4:30 position if viewed from above.
• If the pattern is between 12 o’clock and 3 o’clock, it is over gassed.
• If the pattern is between 4:30 and 6 o’clock it is under gassed.

HOW TO INSTALL A DISSENT UPPER AND END PLATE

• Start with an assembled lower receiver minus the buffer, buffer tube, buffer retainer, or buffer retaining pin (you will not need any of these parts).
• You should have a rear takedown pin, takedown pin detent, and takedown pin detent spring left over (you will be using these).

1. Insert the rear takedown pin from the right of the lower into the takedown pin hole. This should be oriented the same as the pivot pin.
2. Insert the takedown pin detent into the hole on the back of the receiver.
3. Insert the takedown pin detent spring into the hole on the back of the receiver.
4. Align the receiver end plate on the back of the lower. Making sure that the alignment tab is inserted into the recess on the lower.
   1. Use caution with this step as not to bend or kink your takedown pin detent spring.
5. Applying pressure to the end plate to hold it in place, start screwing the end cap plug into the lower receiver.
6. Finish tightening the end cap plug with a 3/8” hex wrench and torque to 40 ft/lbs.
7. Align the picatinny rail over the end plate and end cap plug, making sure to keep the straight ends, and rounded end aligned with their complimenting pieces.
8. Install the supplied mounting screws with a 1/8” hex wrench and tighten.
9. Take your DISSENT upper and align it onto the lower.
10. Close the pivot pin and rear takedown pin.
11. Perform a function check of the firearm.

TROUBLESHOOTING

Selector will not engage “SAFE”

Unload pistol first.

Magazine fails to lock into magazine well

Ammunition will not feed into chamber

Unload pistol first.

Failure to Extract

Unload pistol first.

Bolt Fails to Lock Open on Last Round

Short stroking

Cartridge Jammed in Action

Warning: If this procedure fails to resolve the jam, do not attempt to disassemble the rifle. Consult a qualified gunsmith.

LIFETIME  QUALITY GUARANTEE

CMMG, Inc. will guarantee its products against defects in material or workmanship. CMMG, Inc. will repair, replace or substitute part(s) (at CMMG, Inc.'s discretion) at no charge to the customer if a defect in material or workmanship is found. All service work must be carried out by CMMG, Inc. Please provide a copy of the Invoice or Proof of Purchase when requesting service or repair work. Learn More.

Notice:

All CMMG firearms are designed to function with a wide variety of factory-loaded ammunition and undergo rigorous testing prior to release to ensure reliability and durability. Because CMMG relies on factory ammunition for testing, we cannot guarantee reliable function with handloads or reloads. Warranty claims due to handloads or reloads will be subject to review.

NEED ADDITIONAL HELP?

Contact customerservice@cmmg.com for any questions not answered above.