The AR-15 is a remarkably adaptable platform, but even the most reliable rifle will occasionally hiccup. Knowing how to diagnose and correct common malfunctions keeps you safe, gets you back on target faster, and helps you avoid unnecessary parts replacement. This guide walks through the most frequent AR-15 problems, what typically causes them, and practical, safety-first steps to troubleshoot and resolve them. Throughout, prioritize safe handling: treat the rifle as loaded, keep the muzzle pointed in a safe direction, and remove the magazine and clear the chamber before inspecting or working on the gun.

Understand the Basics: how the AR-15 cycles

Before troubleshooting, it helps to refresh the basic cycle of operation. When a round is fired, gas pressure from the barrel (direct impingement systems) or an operating piston cycles the bolt carrier group (BCG) rearward, extracting and ejecting the spent case and compressing the buffer spring. The buffer spring then pushes the BCG forward, stripping a fresh round from the magazine and chambering it. Proper timing, gas volume, extractor tension, magazine feed geometry, and clean/lubricated parts all must work together for smooth semi-automatic operation. Disruption in any of these areas leads to malfunctions you can diagnose.

Failure to Feed (FTF): common causes and checks

Failure to feed — when the next round doesn’t chamber — is one of the most common complaints.

Common causes:

Faulty or worn magazines (damaged feed lips, weak spring, deformed follower).

Dirty or sticky bolt carrier group or charging components.

Insufficient gas (undergassed system, clogged gas port, misaligned gas block).

Ammo that's out of specification (short overall length or weak powder charge).

Buffer and spring mismatches that slow or shorten bolt travel.

How to check:

Swap magazines with a known-good unit. If the rifle runs, the original magazine is suspect.

Inspect the feed lips and follower — small bends or burrs can produce repeated FTFs.

Clean and lubricate the BCG and chamber; carbon buildup can impede feeding.

Inspect the gas system alignment and clean the gas port/tube.

If using non-standard ammo, test with a reputable brand of factory loads.

Failure to Eject (FTE) and stovepipes

Failure to eject occurs when a spent casing is not thrown clear of the ejection port, often getting partially trapped (a stovepipe).

Common causes:

Weak extractor spring or damaged extractor claw.

Broken or worn ejector spring or poor ejector geometry.

Insufficient gas pressure to impart full rearward energy.

Excessive carbon on the BCG or extractor.

Ammo inconsistencies causing low-pressure cycles.

How to check:

Inspect the extractor claw, spring, and o-ring (if present). Replace worn components.

Clean the extractor recess and the bolt face; carbon lodges here and causes failures.

Verify gas key staking and gas key torque; loose or unsealed gas keys reduce gas flow.

Try different ammo to rule out weak loads.

Double Feed: what it looks like and how to clear

A double feed happens when two rounds attempt to occupy the feed path, typically jamming the action.

Typical causes:

A magazine that allows two rounds to present at once (damaged feed lips or follower).

Extractor failing to hold the spent case, allowing a live round to slide under the bolt.

Bolt override or timing issues from excessive bolt velocity.

How to respond:

Clear the rifle safely: remove magazine, lock the bolt back if possible, clear any live rounds from the feedway.

Replace suspect magazines and inspect followers and feed lips.

Check extractor and spring tension, and clean the chamber.

If bolt override is suspected, check gas system and consider an adjustable gas block or tuning buffer weight.

Failure to Fire and light primer strikes

When the trigger is pulled and only a click is heard, investigate whether the firing pin is reaching the primer with adequate force.

Possible causes:

Worn or weak hammer spring (reduced hammer energy).

Dirty firing pin channel or broken firing pin retaining pin.

Aftermarket triggers with reduced hammer force or incorrect installation.

Bad primers or improperly seated ammunition.

Troubleshooting steps:

Confirm the rifle is cleared and inspect the bolt and firing pin for damage, debris, or corrosion.

Check the trigger/hammer assembly for proper function and spring tension.

Try different reputable ammunition to eliminate the ammo variable.

Replace springs or components showing wear.

Short-stroking: symptoms and solutions

Short-stroking occurs when the bolt carrier group doesn't travel far enough rearward to complete extraction, ejection, and feeding — commonly seen as the bolt failing to lock back or failing to feed the next round.

Why it happens:

Undergassed rifle (clogged gas port/pipe, misaligned gas block, too small gas port).

Heavy buffer or overly strong buffer spring in a gun tuned for lighter cycling.

Ammunition that produces low gas pressure.

Excessive friction in the BCG or receiver rails.

Fixes to try:

Clean the gas system and confirm correct gas block alignment.

Test with different buffer weights or springs that match your barrel/gas system length.

Use a chronograph or trusted data (if available) to confirm your loads generate adequate pressure, or simply test with factory ammo known to cycle AR-15s reliably.

Ensure the BCG moves freely in the upper receiver and that carrier rails are smooth and properly lubed.

Bolt override and bolt ride-up

Bolt override — when the bolt rides over a fresh cartridge instead of chambering it — is often tied to magazine or timing issues.

Typical causes:

Damaged or loose magazine follower.

Overgassed rifles where bolt speed is excessive; the bolt outruns the magazine feed.

Weak magazine spring.

How to address:

Replace suspect magazines immediately.

Evaluate gas system tuning — an adjustable gas block can tame bolt speed.

Consider testing a slightly heavier buffer and spring combination to slow bolt velocity.

Gas system oddities and suppressed shooting

The AR’s gas system directly affects reliability. When shooting suppressed or when swapping barrel lengths and gas block types, expect differences in timing and behavior.

Key points:

Suppressors add backpressure and can overgas a system that was marginally tuned, leading to increased bolt velocity, extractor stress, and faster wear.

Shorter barrels with carbine-length gas systems produce different dwell times; match buffer and spring to the setup.

If you experience sudden changes after installing a suppressor, consider an adjustable gas block or a tuned buffer system.

Magazines: the most-cited culprit

Many problems trace back to magazines — damaged feed lips, weak springs, or dirty followers. Always test with multiple magazines when troubleshooting. Use quality magazines from reputable makers and rotate them, and don’t assume a magazine is good just because it looks fine; springs lose tension with use.

Ammo quality and its outsized role

Ammo influences every aspect of cycling: feeding, extraction, ejection, and ignition. Cheap or out-of-spec ammo will confuse a perfectly functioning rifle. When diagnosing problems, first test with known-good brass-cased factory ammo before replacing parts.

Routine maintenance to prevent malfunctions

Prevention beats cure. Regularly:

Clean and lightly lubricate the BCG and charging components.

Inspect and replace extractor springs, gas rings, and small springs as they show wear.

Confirm gas key torque and staking.

Keep spare magazines and test them periodically.

Use correct torque values for muzzle devices and consider using appropriate threadlocker where recommended.

When parts replacement is the right call

If diagnosis points clearly to a failing component — cracked extractor, deformed feed lips, or a broken spring — replacement is the practical choice. Use quality OEM or proven aftermarket parts and, when in doubt, consult a reputable gunsmith for fit/installation questions. Replacing small parts before they fail completely avoids in-field malfunctions.

Common misconceptions: AR-14 vs AR-15 and naming

There’s occasional confusion about nomenclature — often centered around AR-14 vs AR-15 — with some people referencing “AR-14” in conversation, usually as a misnomer or misunderstanding. The real-world platform standard you’re working with is the AR-15, which has a well-documented set of failure modes, parts compatibility, and maintenance protocols. Mislabeling a rifle or its components can lead to using the wrong troubleshooting guides or ordering incorrect parts, so it’s important to be precise: know you’re dealing with an AR-15 and not a fictional or misnamed variant.

Field-expedient clearing vs. bench repair

In the field, prioritize safe clearing and getting the rifle to a state where you can move or finish firing if safe and necessary. Field clearances remove immediate hazards and allow you to assess whether a simple magazine swap or aggressive charging handle pull clears the issue. Bench repair — disassembly, in-depth cleaning, component replacement — should be done in a controlled environment with the rifle unloaded, tools in hand, and parts replacement guided by manufacturer specs or a qualified gunsmith.

When to consult a gunsmith

If you suspect headspace problems, cracked bolt lugs, gas key issues that won’t seal, or unusual wear patterns, stop firing and consult a gunsmith. These conditions are beyond simple troubleshooting and require professional measurement and possible re-machining.

Final checklist and testing protocol

Confirm rifle is clear every time before inspection.

Reproduce the malfunction in a controlled environment using known-good magazines and ammo.

Clean and lubricate the BCG and chamber; inspect for wear.

Swap magazines and test different ammo brands.

Check gas system alignment and cleanliness.

Replace worn springs and extractors as needed.

If problems persist, consult a gunsmith.

Closing thoughts

Troubleshooting common AR-15 malfunctions is largely a process of elimination: start with the simplest and most frequent causes (magazines, ammo, fouling), then move to gas timing, springs, and parts wear. Keep a maintenance log, rotate magazines, and don't ignore small signs like light primer strikes or inconsistent ejection patterns — they often precede bigger failures. If you’re prepping a rifle for a critical event, and you’re considering parts or spares found on marketplaces, remember that listing quality and seller reputation matter; for example, when researching parts options, a quick check on GunsAmerica can sometimes reveal hard-to-find components and pricing, but always verify compatibility before purchase.