FAILURE TO FIRE
WARNING – If an unfired round has any issue being chambered (jams or binds), do not attempt to force it into the chamber by pushing or striking the bolt forward. This could cause the cartridge to burst resulting damage, serious personal injury and/or death.
WARNING – Always wear safety glasses when attempting to remove a jammed cartridge and turn the ejection port away from you.
- Inspect firing pin and firing pin spring.
Field strip and ensure that the firing pin can move freely within the bolt to fully protrude and return to its at-rest position. Check to ensure firing pin is in good condition and is assembled correctly. - Inspect hammer and hammer spring.
Ensure that the hammer and hammer spring are installed correctly and are in good working order. Commercial firearms are shipped with a lightweight hammer spring to increase reliability across a range of ammunition types. In some scenarios, the heavy duty hammer spring may be installed to increase reliability. - A fatigued recoil spring not chambering cartridge fully.
Make sure the bolt and barrel are fully locked into the forward position prior to firing. If the bolt/barrel does not fully seat into the proper location the hammer will be blocked by the geometry of the bolt. try different ammunition if the bolt and barrel continue to fail to lock fully forward. If trying different ammunition does not work, you may need a new recoil spring. - Dirty or dry action.
Clean and lubricate firearm. - Bolt not fully released.
Releasing bolt forward too slowly with charging handle, try releasing the bolt forward by pressing on the paddle of the bolt catch or pull charging handle fully to the rear and let go rapidly. - Too many rounds in magazine creating drag.
Ensure magazine is not overloaded. - Magazine or chamber is not loaded correctly.
Release magazine, check chamber, and reload. - Defective ammunition.
Discard ammunition and reload with new ammunition. - Too much oil/preservative/CLP in firing pin recess.
Use a clean cloth to remove excess oil.
FAILURE TO EXTRACT
Things to check if you have failure to extract:
- Dirty or corroded ammunition.
Clean chamber and use new, clean ammunition. - Broken or worn extractor spring.
Replace extractor spring. - Broken or worn extractor.
Replace extractor. - Fouling or carbon on extractor.
Clean bolt, extractor and chamber. - Carbon or dirty chamber.
Clean chamber and barrel extension. - Broken or worn ejector arm.
Replace ejector arm.
FAILURE TO FEED
Things to check if you have failure to feed:
- Ensure the magazine is inserted properly
Re-insert magazine and ensure it is locked into place. - Too many rounds in magazine
Make sure magazine is not overloaded. - Compatible magazine
Make sure you are using the magazine that was shipped with the firearm or replacement Magpul CZ-style magazine. - Fatigued recoil spring
Contact nemoarms.com/support to replace part. - Dirty and/or dry action
Field strip and clean firearm, including bolt carrier group, upper receiver assembly and barrel. Re-lubricate. - Dirty ammunition or dirty magazine.
Clean magazine and use new, clean ammunition. - Defective magazine feed lips, spring.
Discard and replace with new magazine. - Round doesn’t load on new magazine.
In some cases, it may be necessary to load the firearm from a fully loaded magazine by pulling the charging handle fully to the rear and rapidly letting go. - Bullet shape.
Some flat-nosed , full metal jacket , and jacketed hollow point projectiles may not feed reliably. - “Short Stroke” condition (see below)
SHORT STROKE
A so-called “short-stroke” failure is when the bolt does not fully go rearward after a shot is fired. There are different levels of this type of failure that can result in different types of diagnosis. When the bolt does not have enough rearward inertia after a round is fired it can cause failure to eject, failure to fire, failure to feed, or failure to lock to the rear after last round in a magazine is fired. Primary causes are:
- Low-Power ammunition.
Try using ammunition loaded with a heavier bullet or higher velocity. - Dirty and/or dry operating system.
Clean and lubricate bolt, barrel, and upper receiver. - Suppressor use.
Suppressor is too heavy, booster device is not working properly. - Poor grip.
Firmly hold the firearm with two hands to reduce movement.
FAILURE TO LOCK OPEN AFTER LAST ROUND
Things to check:
- Low-Power ammunition.
Try using ammunition loaded with a heavier bullet or higher velocity. - Issue with magazine follower.
Ensure magazine follower is in good condition and has good interface with bolt catch arm.
ACCURACY
If you are experiencing accuracy issues:
- Low quality ammunition
Use high quality match grade ammunition, try different ammunition. - In-accurate install and setup of optic mounts and rings
Ensure optics are torqued to the correct specification and ensure your optic is set up properly. - Dirty barrel
Your barrel may have too much carbon and copper fouling, clean carefully with copper solvent, follow solvent manufacturer’s instructions. - Throat erosion.
Barrel has reached it’s service life.
BLOWN PRIMERS / PIERCED PRIMERS
Things to check if you have failure to extract:
- Inspect the bolt for damage
- Remove and inspect firing pin for damage and debris
- Switch ammunition
- Contact NEMO Arms support (nemoarms.com/support), there may be damage to the firearm that needs to be repaired before firing another round.