Army Begins To Upgrade M4 Carbines To M4A1 Configuration

M4A1 - GUNS 2

During a press conference earlier this week at Ft Riley, Kansas, the Army’s PEO Soldier announced that they have begun to upgrade M4 carbines to the M4A1 configuration beginning with the 1st Infantry Division. The process will convert 500,000 of the weapons at a cost of $120 Million over the next five years with the fielding plan being controlled by Department of the Army. This press conference also served to dispel rumors that I have heard that they Army plans to pure fleet to the M4A1 configuration and upgrade its M16A2/A4 currently used by many non-Combat Arms Soldiers. They aren’t, and nothing is currently planned for the existing M16s.

“Upgrading M4s to the M4A1 configuration will deliver increased sustained rate of fire, durability, and enhanced ergonomics for the Soldier,” said Lt. Col. Shawn Lucas, PM IW. “The Army’s priority is to maintain the best equipped land force in the world, and to ensure it is postured to fight and win any conflict.

“Looking to the future, the Army will continue to monitor industry and government advancements in small arms to inform future requirements for leap-ahead technologies in range, accuracy, lethality and reliability,” Lucas added.

It’s important to note that these aren’t the first M4A1s in the Army. SOF troops have been wielding the weapon since 1994 as part of the SOPMOD (Special Operations Peculiar Modification) program and some Army units were fielded M4A1s in 2012. This implementation of the Dual Path Strategy that offers an incremental upgrade to existing carbines, was one of two plans to improve the lethality of the Individual Soldier. The other leg of the Dual Path Strategy was the Individual Carbine program which was halted last year after failing to identify any significant improvement over currently fielded systems.

Of note, is the claim by PEO Sergeant Major, CSM Doug Maddi, that the M4A1, when used with the new M855A1 ammo, offers “58 basic loads mean rounds between stoppages.” That’s pretty impressive, considering a Soldier Basic Load of Ammunition is 210 rounds. They’re getting upwards of 12,000 mean rounds between stoppages.

M4A1 Carbine Product Improvement Program

The M4s will receive a new, heavier barrel, ambidextrous safety and a conversion from 3-round burst to full-auto fire. Technicians from Anniston Army Depot, Alabama and TACOM are performing the Modification Work Order upgrades on site at Ft Riley. They are moving along at a pretty good pace, upgrading about 300 Carbines per day. The extent of the MWO can be seen in the graphic above.

M4A1 - General warehouse shots 1

Contracts for the new components required for the upgrade were awarded in March. Both the M4 Replacement Barrel and Front Sight Assembly (Heavy Variant) are from Colt Industries, owner of the M4 patent. OG TECHNOLOGIES INC and Manufacturing Support Industries, Inc are providing the M4 Fire Control Selector Assembly.


The maintenance team will install pre-built upper receiver assemblies, replace the trigger assemblies and install ambidextrous selector switch. The old M4 upper receivers will head to Anniston to undergo inspection where some will become part of future MWO kits. In addition to installing the new parts, the team will also use a laser engraver to alter the weapon’s designation to M4A1 and add “Auto” markings to the lower receiver in place of the current “Burst” designation.


But this is just stage one, with a Block II MWO coming in the future. Additional upgrades the Army plans to incorporate into the M4A1 include a new Modular Handguard, Bolt Carrier Group and possibly a Match-Grade Trigger. The Army also continues to consider the wider use of suppressors.

In the end, you can look at this one of two ways. On one hand, the Army’s Dual Path Strategy was a good investment and is improving the Soldier’s Carbine. I applaud them for doubling down to make sure that a great weapon was made even better. On the other hand, the Army is just now standardizing what SOCOM has had since 1994. The photo below depicts an Army Special Forces NCO in the mid-90s equipped with an M4A1 and looking at his equipment it almost gives you a feeling of nostalgia. It kind of feels like an opportunity lost.


The PIP was pretty conservative and didn’t leverage much of the improved small arms technologies we’ve seen from industry over the last decade, since the sunset of the so-called Assault Weapons Ban which stymied innovation in the US firearms industry from 1994-2004. Hopefully, the Army will continue to engage industry and provide additional enhancements to the Soldier’s most basic weapon; his Carbine.

(Thanks to PEO Soldier’s PAO team for the photos and to the participants in the press conference: LTC Shawn P. Lucas, Product Manager Individual Weapons, Picatinny Arsenal, NJ, CSM Doug Maddi, PEO Soldier Command Sergeant Major, Ft. Belvoir, VA and CW3 Charles Havner, 299th 2nd Brigade, 1 Infantry Division, Ft. Riley Kansas .)

26 Responses to “Army Begins To Upgrade M4 Carbines To M4A1 Configuration”

  1. Reklaw says:

    I’m having trouble deciphering that first paragraph. What exactly will be happening to m16a2/a4s?

  2. Tyler says:

    2ID Korea has started the conversion as well.

  3. Jim says:

    Not a bad decision. Curious what the BCG upgrade could be.

    • Roger Nitchman says:

      BCG stands for Bolt Carrier Group this is in the Upper Receiver. This cycles the rounds working with the exhaust gas and has the firing pin to strike the primer of the shell when the trigger is pull. I’ve left a few things out but you get the basic idea.

      • Ron says:

        I’m pretty sure he meant he was curious as to what upgrades will be made to the bolt carrier group….

        • Joshua says:

          No telling. Most likely just an enhanced bolt like the LMT Enhanced bolt or the Sharps Relia-Bolt.

  4. Riceball says:

    From the looks of the picture it looks like the Army isn’t going to be using modular handguards with their A1s, pity since it would save some weight and make the weapon more comfortable.

    Also, does anyone else find it odd that combat arms troops are getting issued M4s but the rear echelon/non-combatants get M16s? Isn’t that kind of backwards from how everybody, including us, normally does it; the rifle for the front line troops and carbines for everybody else?

  5. Carlos says:

    “Dual Path Strategy” = a carbine replacement dog and pony show designed to fail while appeasing the politicians temporarily while the Army does what it wants and makes 20 year-old upgrades to the M4.

  6. Bussaca says:

    It looks like the barrel and RIS is shorter? or is that a compressed image..

    The reserves and Nasty Girls will still be useing flint lock rifles.. and as far as full auto.. meh.. it’s nice.. nothing a flat washer to move the 3 round sear out of the way hasen’t fixed in the past…

    Not like youre allowed to ever switch it into the rear position anyways.. I surprised they just didn’t ever switch us all out to civilian lowers a long time ago.. I know joes who don’t even know it goes that direction..

  7. David From Alabama says:

    $120M to convert 500,000 weapons? Couldn’t they just buy new weapons for a fraction of that cost?

    • SSD says:

      The thought did cross my mind.

    • Jms says:

      I don’t know where you can get new weapons for less than $240. It actually sounds like a bargain for the upgrade.

    • Matthew Groff says:

      It is only costing $240.00 per rifle, which is not too bad. That is relatively cheap considering most new barrels can cost over $200 each! And some of the uppers can also cost just over $200 each or more depending on what brand you buy and what options you get included, Some Bolt Carrier Groups can also cost as much as if not more than $200 also!

      So for $240 per rifle for the upgrade is cheap! Especially when you consider the cost of a new rifle costs anywhere from $650 (plain Jane) to upwards of $3000 or more (fully loaded w/accessories) on the civilian market! Of course it depends on the manufacturer and what accessories you have included on the rifle and the brand of the accessories!

      • SSD says:

        The Government doesn’t pay anywhere near what the commercial market demands for a Colt carbine.

        • Joshua says:

          A new M4A1 is still around $679. Good luck getting any new rifle for that cheap that offers any substantial upgrade in parts life or reliability, especially when we can enhance both with COTS items like new bolt designs, handguards, ect.

  8. straycat says:

    heavy barrel and ambi-safety, good idea. but the army got away from Full Rock And Roll FOR A REASON.

    • Bob says:

      ….and after a few decades and several wars, determined that the 3-round burst was not such a good deal and that controlled full auto fire was actually more effective. Full auto fire and rapid fire are very applicable in certain situations. That’s why SOF units went back to full auto carbines years ago.

    • Joshua says:

      Because the Marine Corps got their way in the M16. The reason for,the trigger change is because the auto FCG is less complex and has one precise consistant trigger pull.

  9. J says:

    The Army should have transition to a 16 in barrel with a mid length gas system for these upgrades. This would have made more sense to get a better shooting rifle for the Army plus better muzzle velocity which has been a problem with the 14.5 in barrels.

  10. RICH says:

    I think the changes are not upgrades but down grades, remember, the m16 was changed to 3rd burst because of spray and pray. The gun would overheat and malfunction in full auto. The 5.56 dose not do well in short barrels. I say short barrel in 6.8spc cal. and a piston opp system would make more sense.

  11. Bob says:

    “Upgrading M4s to the M4A1 configuration will deliver increased sustained rate of fire, durability, and enhanced ergonomics for the Soldier,” said Lt. Col. Shawn Lucas–”

    How in the hell does going full-auto “increase durability”, or “enhance ergonomics”?

    It doesn’t. Yes, it allows greater volume of fire to be sent downrage, but it sounds like this PR officer just picked nice sounding ideas out of thin air and threw them in there as well. But I guess that’s his job to make pretty sentences out of things.