Why Is My AR-15 Double Feeding? How Do I Fix It?
Double feeds occur when two rounds try to enter the chamber simultaneously. The most common causes are a worn or damaged extractor that fails to hold the spent case (so it stays in the chamber while the next round feeds), short stroking that prevents full ejection, and faulty magazines with damaged feed lips or weak springs.
Why It Matters
A double feed is one of the most difficult AR-15 malfunctions to clear quickly. It requires locking the bolt back, removing the magazine, clearing both rounds, and reloading — a multi-step process that takes valuable time. Recurring double feeds indicate a mechanical problem that must be diagnosed and fixed rather than simply cleared each time.
The Detail
Double feed diagnostic process:
Type 1 — Failure to extract the spent case:
- The most common double feed scenario
- The fired case remains in the chamber because the extractor failed to pull it out
- The bolt rides forward and tries to feed a live round into the occupied chamber
- Cause: Worn extractor, weak extractor spring, broken extractor claw, or dirty chamber preventing extraction
- Fix: Replace the extractor spring (use BCM enhanced spring kit), inspect extractor for damage, clean the chamber
Type 2 — Short stroke double feed:
- The bolt travels rearward far enough to extract the spent case but not far enough to eject it
- The case gets pushed back into the chamber area as the bolt goes forward with the next round
- Cause: Undergassing (gas block alignment, gas key leak, buffer too heavy)
- Fix: Address the gas system issue (see short stroking diagnosis)
Type 3 — Magazine-induced double feed:
- Damaged magazine feed lips allow two rounds to present simultaneously
- Worn magazine springs do not push rounds up with enough force, causing timing issues
- Bent or dented magazine body causes rounds to stack incorrectly
- Fix: Try different magazines. If the problem goes away, discard the faulty magazine
- Quality magazines: Magpul PMAG Gen M3, Okay Industries SureFeed, Lancer L5AWM
Clearing a double feed:
1. Lock the bolt to the rear
2. Remove the magazine
3. Rack the charging handle several times to clear both rounds
4. Inspect the chamber — ensure it is empty
5. Reinsert magazine and charge the rifle
If double feeds occur with multiple magazines and different ammunition, the problem is the rifle (extractor or gas system), not the magazines.
Build Impact
For new builds, double feeds that start immediately point to an assembly issue — usually gas block alignment causing short stroking. If the rifle ran fine initially and double feeds developed over time, suspect extractor wear or carbon buildup. Keep spare extractor springs and O-rings in your range bag. Inspect your extractor every 2,000 to 5,000 rounds and replace springs proactively.