Marines will not upgrade M4 Carbines

The Marine Corps Times reports that the USMC will not be upgrading their M4 to the newer version that the Army is busy developing …

As the Army moves to field more than 10,000 conversion kits designed to make the 5.56mm M4 deadlier and more reliable, the Marine Corps says it has no plans to update its inventory.

Nearly all infantry soldiers use M4s, but in the Corps they are fielded primarily to vehicle operators and other Marines whose jobs render the primary service rifle, the M16A4, too cumbersome. The Corps has no plans to upgrade either rifle, Lt. Gen. George Flynn, deputy commandant for combat development and integration, told Marine Corps Times on Aug. 23.

This does not surprise me. The USMC command is very resistant to the idea that rifles are getting shorter and shorter. Tomorrow’s rifle is yesterday’s carbine.

[ Many thanks to Lance for emailing me the link. ]

Steve Johnson

Founder and Dictator-In-Chief of TFB. A passionate gun owner, a shooting enthusiast and totally tacti-uncool. Favorite first date location: any gun range. Steve can be contacted here.


  • William

    What are the conversion kits that the Army is getting? Haven’t heard anything about this. Personally I’m under the belief that the debate is blown out of proportion. My M16 and M4 never malfunctioned when I was in, no one that I knew ever complained about a malfunction, and my Colt AR-15 A2 has never had a hiccup ever since my dad first bought it in 1991.

  • Josh

    William- Someone conned the army into converting all there M4s in to piston guns with conversion kits. Not a new upper mind you, a kit to replace the gas tube and parts of the bolt carrier. I believe they have some other dumb crap they want to do to them too. I think the article was on Army Times website.

  • Colin

    With the M27 in-the-works as a rumoured backdoor replacement for the M-16 / M-4 are you surprised that the Marines dont want anything to do with these upgrades?

    Always wondered why the Marines don’t go for a bullpup (even with Americans dislike for them). The long barrel in a short package must be attractive to them. If the USMC put out a tender for a fully ambidextrous bullpup with barrel options of 12, 16 and 20 inchs Colt would be falling over themselves to develop it, hell FN are close with the F2000…

  • SpudGun

    Two things to consider that may or may not be relevent –

    1. There is tremendous rivalry between the services – if the Army does something, then the Marine Corp might do the opposite just out of spite / tradition / requirements. Such as the M4 vs the M16.

    2. The Corp have always been a bit ‘maverick’ over their procurement, they might be resisting the upgrade so they can spend their dough on a new rifle. With HK IARs currently in theatre, it could be the Marines’ way of trialing a new system.

    As usual, this is all speculation on my part and I’m probably talking out of my hat.

  • Yogsothoth

    “never version” Steve? Typo or clever jibe at the slowness of the development process?

    • Yogsothoth, haha, typo 😉

  • jdun1911

    Take anything the Army time said with a grain of salt. It’s not part of the US military and their writers are dumb.

    Tell me if Bullpup are good than why Special Operators do not use them when their military made Bullpup standard? Because there is too much flaws to justified a 20″ barrel into a smaller package.

    The Marine has priorities like upgrading their M16A4. They wants to upgrade the M16A4 with a collapsible stock and Vltor A5 look very promising.

    Marines do their things. Army do their things. Both have different set of missions, some overlap but mainly different. It’s not rivalry it just how it is.

    • jdun1911, I know their writers, they are not stupid. They sources are usually high ranking officers and they usually publish quotes. Any stupidity comes from lack of cohesion in the high command.

  • Lance

    Besides buying thousands of conversions kits the Army is buying around 37,000 M-4A1s from a unmentioned maker (probably Colt) for fielding with pistons as well. This is the M-4 update program.

    The M-27 and the SR-556 will be in the next carbine competition. the Army says its going to field new M-4s and look into new carbines like the M-27.

    As Steve believes too, the M-4 is going to be around for at least years longer.

  • Cameron

    Ughhh Marines and their aversion to progress

  • Moose

    “The Corps has no plans to upgrade either rifle,”
    I wonder if this statement includes the Vltor A5 system?

  • vereceleritas

    I could care less if we “upgraded” our M4’s or not but I definitely prefer rifles to carbines. M4’s have their advantages but I can’t understand the fascination over carbines. They’re so short they almost feel like toys. They’re easier to maneuver and carry but isn’t the shortened gas system and 14.5in barrel the source of the reliability, lethality and range issues that some units are having in Afghanistan? I’ve also noticed that most complaints about service rifle reliability come from the Army and not the Marines.

    A lot of my Marines like M4’s because they’re light and easy to carry but many of them (me included) have a marksman’s mindset instilled in us since boot camp and would like the option of being able to reach out and touch somebody at 500m.

    I think an M16 with a collapsible stock, a 18in barrel, and a lighter rail system like the MK12 SPR would be a good compromise.

  • Nadnerbus

    Considering the budget cuts coming down the pipe, I think the Corps are more interested in getting their Expeditionary Fighting Vehicle and more Ospreys than fixing a weapon that really isn’t broke.

    Personally, I think the Army is wasting their money.

  • Lance

    I wont put a M-16A5 out tof the question in a few years But the Corps hasnt bought all the A4s they wanted I know many men in the local Marine reserve unit who have M-16A2s. I think the IAR will get ptiority then talk about a upgrade M-16A5 might come.

    All of the M-16A2s the Marines had in front line units have been given to the Navy, to Seebees and Security forces, Marine Reserves still use alot of them too. So dose the USAF and USCG.

    I dont see the A4 going anywhere, agree Steve?

    • Lance, many Marines in the field say they are using M4’s. I think Marines everywhere else are using A4’s.

  • jdun1911

    For my own experience Army Time is not place to for good source of information.


    From what I understand Vltor was tasked by the Marines to make a collapsible stock for the M16A4. The A5 might or might not replace the current fix stock.

    The problem with the A2 stock is body armor. If you’re not a tall guy the body armor gets in the way. That’s why in some pictures you will see Marines putting the stock over their shoulder while shooting in Iraq or Afghanistan. The A2 would be find if body armor wasn’t involve but that’s not the case anymore.

    A normal collapsible while it will work find in semi-rifle it will have trouble in auto-burst-rifle (20″ inch barrel) via bolt bounce. The A5 is suppose to prevent that from happening.

  • Moose

    Good insight, jdun1911. Thanks.

  • Lance

    I know the USMC is being used Steve. All NCOs Officers and vehicle operators use M-4s like how a carbine is supposted to be used. I ws saying the Corps has no plans in a next few years to replace the A4 for grunts and rilfeen in the feild.

    Thats what I was aksing you Steve. Sorry for the confuse you.

  • Caseless

    The Marine Corps decision is right. 5.56×45 with a barrel length < 20-inch just does not make sense. It's way too limiting on the worldwide battlefield. FN and Kel-Tec have the right design direction for bullpup rifles.