M4/M4A1 Carbine Reliability Issues: Why They Occur , and Why They’re Our Fault! Why M4’s have reliability issues…and why it’s our fault! By Michael Pannone December 24, 2008 I fired 15,000 ro unds through a semi-automatic M4/M4A1-type direct-gas-impingement (DGI) carbine in 31 weeks without a single malfunction attributable to anything except bad ammunition or bad magazines, with a grand total of 9 malfunctions. The least number of rounds fired between cleanings was 960 rounds, and the only parts replaced were gas rings at 8,860 rounds. And you can, too. The M4/M4A1 Carbine is simultaneously a much beloved and much maligned rifle. But why? It’s beloved because it is so simple to maintain and ergonomically the best-designed assault rifle/carbine system of all time. It’s maligned because many have not maintained it as they should, and reliability has subsequently suffered. If the M4/M4A1 is properly maintained, and a reasonable amount of lubricant is put on it, it is extraordinarily reliable. We need to… define “maintained” or better yet, redefine “weapons maintenance”. Through the years “weapons maintenance” has meant “weapons cleaning” with little if any emphasis on inspection or parts replacement. “Vehicle maintenance” is not “vehicle cleaning”, although cleaning is an element ofvehicle maintenance. The true definition of Weapons Maintenance is: maintaining the reliable operation of the weapon through inspection, cleaning, AND parts replacement. The parts that need inspection and replacement periodically to maintain optimum reliability are those most related to feeding, extraction and ejection, and most prone to wear or fatigue. This includes
Why M4’s have reliability issues…and why it’s our fault!By Michael Pannone
December 24, 2008
I fired 15,000 rounds through a semi-automatic M4/M4A1-type direct-gas-impingement (DGI) carbinein 31 weeks without a single malfunction attributable to anything except bad ammunition or bad
magazines, with a grand total of 9 malfunctions. The least number of rounds fired between cleaningswas 960 rounds, and the only parts replaced were gas rings at 8,860 rounds. And you can, too.
The M4/M4A1 Carbine is simultaneously a much beloved and much maligned rifle. But why? It’s
beloved because it is so simple to maintain and ergonomically the best-designed assault rifle/carbinesystem of all time. It’s maligned because many have not maintained it as they should, and reliability has
subsequently suffered. If the M4/M4A1 is properly maintained, and a reasonable amount of lubricant is put on it, it is extraordinarily reliable.
We need to…define “maintained” or better yet, redefine “weapons maintenance”. Through the years “weapons
maintenance” has meant “weapons cleaning” with little if any emphasis on inspection or partsreplacement. “Vehicle maintenance” is not “vehicle cleaning”, although cleaning is an element of
vehicle maintenance.
The true definition of Weapons Maintenance is: maintaining the reliable operation of the weaponthrough inspection, cleaning, AND parts replacement.
The parts that need inspection and replacement periodically to maintain optimum reliability are those
most related to feeding, extraction and ejection, and most prone to wear or fatigue. This includes
magazines, especially. If we remove magazines from the equation as an extremely problematic item, theremaining parts critical for inspection and routine replacement are the extractor and spring. From my
experience they are the biggest culprits in M4/M4A1 malfunctions, aside from bad magazines.
The rifle at the individual level is often extremely well cared for. But, at the unit level, it is routinely andeven institutionally neglected. Think about it. When was the last time a unit went through all its rifles
pre-deployment and replaced the extractor and spring and the gas rings? When do units “overhaul” theguns? By “overhaul” I mean gauging the barrel to check remaining life and overall serviceability and
replacing the extractor and spring, ejector and spring, gas rings, and buffer spring. Do they issue newmagazines for soldiers to take into combat on each deployment?
These parts, to include magazines, are the most common reasons for failures. And yet, as an institution,
the military does very little until the gun actually stops working! Rifles are shot until they break for lack of a better description, and magazines are used and reissued many times even when unserviceable. This
doesn’t end until someone crushes them so they cannot be reissued. This is the functional equivalent of driving a vehicle until it breaks down before getting it serviced. It may sound like an exaggeration, but
many reading this know it is, in fact, more the rule than the exception. And it has to change.
I was one of the first primary instructors on the U.S. Army Combat Applications Training Course withthe Asymmetric Warfare Group (AWG). I helped write and structure much of the content and worked
with Cav units, Brigade Support Battalions, Airborne and Airmobile infantry units, as well. Each of these units exhibited two specific traits:
1. The soldiers did not really know how their weapons worked (direct impingement theory) or didn’t
work (why malfunctions happened) nor how to remedy malfunctions other than using immediate action(SPORTS).
2. There was no specific overhaul schedule prior to deployment to Iraq or Afghanistan.
I have personally fired 15,000 rounds through a 14.5” civilian semi-automatic M4 (Noveske 14.5” N4VTAC Combat Carbine with Crane O-ring from a SOPMOD bolt upgrade kit and Sprinco 5-coilextractor spring) in a 31-week period with 6 malfunctions and 3 failures to fire.
All were attributable directly to bad magazines or bad ammunition. The only parts replaced were gasrings at 8660 rounds and that was preventative and not required. The rifle was still reliable. The rifle was
minimally maintained. Each morning of use it was lubricated with 6-10 drops of Sprinco MachineGunners Lube and a bore snake run through the barrel. Detailed cleaning was done at the following
round counts:
1. 1150rds2. 2110rds
3. 4210rds4. 5940rds
5. 8660rds6. 11,745rds
7. 15,000rds
Malfunctions:1. 06/10/08 double feed ( personal magazine marked #7)
2. 06/11/08 double feed ( personal magazine marked #7)3. 06/19/08 double feed GI magazine w/ black follower (unmarked student magazine)
4. 08/02/08 double feed ( personal magazine marked #8)5. 08/02/08 case separation with reloaded 55 grain FMJ 5.56mm
6. 08/10/08 double feed with GI green follower magazine (unmarked student magazine)7. *08/10/08 failure to chamber and lock (2 rounds) dud (1 round)
Author’s Note: While at XXXXX in Ft Bragg, I and one of the instructors picked up 30 rounds found onthe ground at one of the shooting points. These rounds had obviously been there for weeks (at a
minimum) and were tarnished, and some were borderline corroded. We loaded and fired 27 of 30rounds. Two rounds were bent and would not chamber, one was a dud.
So, what should be done?Maintenance!
1. Overhaul the gun every 5,000 rounds, or prior to any operational deployment. Use the existing and proven BHI Enhanced M4 SOPMOD Bolt Upgrade Kit (extractor/spring and Crane O-ring, extractor pin, gas rings) as well as a new buffer spring on rifles with more than 15,000 rounds on the original one.
The M4 SOPMOD Bolt Upgrade Kit is a proven refurbishing kit that will dramatically increase
extraction reliability. The new extractor is of obvious benefit, the O-ring will give the extractor four times the tension, and the gas rings are necessary to trap enough gas to effectively propel the bolt carrier
to the rear. Gas rings are prone to wear because of their repeated exposure to extreme pressure, heat andfriction. (This friction is dramatically exacerbated when dust and sand are introduced via the operating
environment.) The buffer spring (actually the action spring for all you nomenclature fascists) is oftenoverlooked but is critical to absorbing the energy of the recoiling bolt carrier group and ensuring that it
is propelled forward with enough energy to positively feed chamber and lock a live round even in a dryand dirty rifle. Worn out buffer springs often cause battering of the rifle, double feeds and failures to
properly feed, chamber and lock. On my rifle, I use a Sprinco Super Duty M4 buffer spring as well as aDPMS Extra-Heavy Buffer (it is .2oz lighter than an H3 buffer). This combo makes my rifle super
reliable and extremely soft shooting. (*The rifle must have a mil-spec gas port and a barrel of 14.5” or 16” with carbine gas system. On mid-length gas system guns, use the Sprinco standard CAR-15 spring.
This spring and heavy buffer do not consistently work in Rock River Arms rifles, from my experience.)
2) Make it service/agency wide SOP that all magazines are marked in a numerical sequence with theoperator’s initials/call sign/ battle number or some other individual marking traceable to him.
If both of these actions are taken there are two distinct benefits:
a. If the rifle malfunctions, the operator will be able to diagnose if it is magazine related and trace it tothe unserviceable one. If unserviceable magazines are marked with red spray-paint on the bottom 1/3,
they can be kept for training. This allows the operator to conserve operational magazines and get extratraining on malfunctions as they could occur.
b. Properly marked magazines can always be returned to the original operator and if found on anobjective will tell other elements who was there prior to their arrival.
*I prefer chrome silicon (CS) springs over stainless steel (SS) because they take minimal set. I am a big
proponent of no-tilt followers, as well (Nearly all my magazines have MAGPUL Enhanced Self-Leveling “No-Tilt” Follower or CMMG Stainless Steel Anti-Tilt (SSAT) Follower. I refitted all my
magazines in Iraq with CS springs and MAGPUL followers). I have used Colt, CMMG, MAGPUL andLancer Systems magazines with great success. I am currently beginning a test on a new magazine and
will be writing an article on magazine selection in general in the near future.
3) Keep a rifle log book with shot record and log of malfunctions per rifle.
4) Create a new training culture:a. Teach carbine theory and true maintenance (this is covered in detail in my M16/M4 Handbook as well
as Green Eyes and Black Rifles: Warriors Guide to the Combat Carbine by my friend Kyle Lamb of Viking Tactics).
b. Refine institutional maintenance so it is more responsive to the end user and overhaul guns yearly or
prior to any operational deployments.
c. Malfunctions: Teach cycle of operations and diagnosis of mechanical failures (also in M16/M4 HB
and Green Eyes).
d. Empower individuals to feel it is their sacred duty to make sure their rifles function properly.
e. Hold individual operators accountable for the performance of their weapons.
Piston-driven guns are all the rage now with the advent of 10.5” sub-carbine barrels. This is because a
piston/op-rod gun omits the need to match the barrel to the gas tube length. That said, on standard 20”and 14.5” formats, direct gas guns are extremely reliable when properly cared for by both individual and
institutional personnel. This takes more knowledge than effort, and it is owed to the men and women inthe field.
Author’s notes:
* This piece is written with the Soldier, Sailor, Airman and Marine in mind. If you are none of the abovetake what applies and disregard the rest. 90% is applicable to most that own or carry an AR-
15/M16/M4/M4A1-series direct-gas gun in any capacity.
* I highly recommend both the M16/M4 Handbook and Green Eyes and Black Rifles: Warriors Guide tothe Combat Carbine as technical training references for all serious shooters.
*I receive no money from Sprinco, but choose to use their products exclusively because they have
worked extremely well under extreme use. All 15,000 rounds were fired on the same extractor spring.
*Any time you change any part, i.e. buffer spring, buffer weight, magazine followers and springs, etc.,test fire the rifle before operational use!
Editor’s Note: The photos accompanying this article were provided by the author (Mike Pannone), and
are copyrighted. The M4/M4A1-type carbine pictured is semi-auto-only, and is the back-up weapon tothe actual weapon the author used for the high-round-count test covered in this article. The pictured
weapon is identical, except that the free-float (FF) Mil-Std-1913 "Picatinny" rail system/forend rail tubeon it is 2" shorter than the one on the actual weapon used. All else, i.e. springs, weights, etc., are the
same.
About the Author: Michael Pannone a.k.a Mike Pannone is currently a Senior instructor for both Team
VTAC (Viking Tactics) and Mid-Atlantic Training Resources (MATR), and a certified Colt Armorer.He is also a former operational member of U.S. Marine Force Reconnaissance, U.S. Army Special
Forces, and specially selected elements of the Joint Special Operations Command. He has participated instabilization, combat, and high risk protection operations in support of U.S. policies throughout the word
as both an active duty military member, and a civilian contractor. During his military career, Mr.Pannone was the Distinguished Honor Graduate of a Level 1 SOTIC held at Ft Bragg. He currently
instructs U.S. military, law enforcement (LE), and private citizens around the country as an adjunctinstructor with several different organizations. He can be contacted via e-mail at ctts at live dot com.
