Inside the Colt CM901

It’s a rifle that’s got a lot of discussion around it — particularly as an option for the Army’s improved carbine competition, assuming they offer it in a gas-piston version.

But the CM901 is a pretty impressive weapon, pairing the latest in carbine refinements with the experience of Colt.

As you can see, it was a bit difficult to get the Colt guy to open up. But there might be some information in here that’s new to Kit Up! readers.

FYI — I did get to fire the CM901 in 308 and thought it shot pretty well…

  • Moondog

    Looks good, but would rather see it in something like 6.8 and .308, or 30BR in the carbine version and .308 in a longer barreld version. The 30 BR is basically the .308 case shortened about a quarter inch. Slightly more powerful than the 7.62 round the AK fires, but with the same case head as the .308 With the 308/30 BR combination you don’t have to switch out bolts. One is very accurate and good out to 200-300 yards, the other is accurate but more powerul, with a heavier bullet out to 6-900 yards.

    No matter how good a firearm Colt comes out with, I am confident that the Army small arms experts will be able to screw it up some way.

  • E5MATT

    …Finally…Colt rifles with a factory installed ambi-safety………..ME LIKEE!!

  • Dave

    “But there might be some information in here that’s knew to Kit Up! readers”

    ‘new’ not ‘knew’ Sorry had to get ya on that type :D

    • Ugh…

      But I think you meant “typo”…;-)

  • Shaun

    Doesn’t look like much of an improvement on the M4, especially considering competitors.

  • Stefan S.

    Sigh… Another M4?

  • Mongo

    The product rep should look for a new job The convertability option is very nice if it functions reliably

  • Infidel4LIFE

    the Hk 416 is pretty highly regarded, you read the comments, see the vid, but how good is the Colt model? Is it better than the 416? Wat is Socom using? Thats a pretty good way to judge wats wat. How much per model?

  • phillip

    Very Good, Like to see it will a little more reach, just to take out the bad guys before they get real close

  • CavScoutSniper

    More overprice junk from the thieves @ Colt. Why the hell we don’t just go to Armalite AR-10’s I’ll never understand. Stoner and Armalite invented the damn system in direct impingement and piston versions way back in the ’50’s and everything else is just an imitation. As far as the AR-10 being a .308Win (7.62X51) well, if you cant handle the little bit of recoil and weight of a .30 cal weapon then you don’t need to be in the Military to begin with. The mouse gun caliber has proven itself to be 100% great for varmint hunters and 100% ineffective for combat. The McNamara/WizKids experiment it over and it was & is a failure. Give our boys a real rifle in a real combat caliber and get on with it!

  • Infidel4LIFE

    CavScout i feel the same about Colt. Its rigged, the whole process. Why not in 6.8mm or a 7.62X51? Its great they finally installed the piston but its still the same round. The Army is not going to change rounds, its pretty clear. How many times do you have to shoot a hopped up dude on drugs and adrenaline? LOL!! SOCOM gets watever they want, they deserve the best gear available. I can recall reading that a SF grp on Okinawa swapped their M-4 uppers for Hk 416’s.

    • Nance, E

      Uh this is a .308 firing rifle which is basically 7.62x51mm. Really not sure where you are getting that it is 5.56mm. I do doubt they will change to 7.62x51mm since, among other things, they just started making and using M855A1.

      As for it being 100% ineffective do you mind explaining how people are killed by it then? If a 5.56mm hits a vital then it will work fine. Miss a vital and it wont do much to stop them this is true of any bullet .50 cal and under. Which means if a 5.56 doesn’t work then it wasn’t a good hit. A larger round wouldn’t do any better in that case. What would miss a vital for a 5.56 would most likely miss with a 7.62. Unless it missed by 2.06mms

  • Guest

    Guys I don’t know why you are all complaining that it should be a 7.62 x 51 (.308). IT IS chambered for that round!!!!!!!!!!!!! You can just stick a 5.56 upper on that lower w/ a block in the mag and run it as a 5.56 / .223 too.

  • Pay attention!

    All your complaints are unfounded fellas. This rifle comes as a 7.62 Nato and can be adapted for 6.8 or 5.56 Nato by swapping uppers and putting a block in the magwell to size it to whatever mags you are using. Next time read the print says .308 up there and listen to the video (he says can be CONVERTED to 5.56). I may be one of the only ones here that likes it but I want one for a new SBR!

  • crackedlenses

    Agreed. There are thousands of Vietnamese, Afghans, and Iraqis who would disagree about the 5.56 mm. round being 100% ineffective, if they were still alive……

  • TMP683

    The NAVY in looking to convert all of their rifles from the M4 to the SCAR in 7.62 NATO. The SEALS, SWCC and EOD will be the first to transition. Then the Coastal Warfare guys, such as myself will transition next.

    But you know how the military works, that’ll be 10 years from now.

    MA1 DM

  • Industry Rep

    *They swapped back, keep up on current events

  • Nance, E

    Swapped back to 7.62x51mm? If so then no. Designated Marksmen use it along with snipers and those with MMGs. The vast majority of US military personnel have a 5.56x45mm firing weapon. The M4 and M16 are the most common weapons in the US military

  • Guest B

    I believe that its operating system is adaptable as well as its caliber; direct impingement, piston, hybrid, articulating link. I’ve seen some rumors about a Colt rifle performing better in the dreaded dust test than the HK416. I guess we shall see in the future.

  • Silly boys

    If you guys think that hitting vitals is the only way a bullet causes damage and the difference between 7.62 and 5.56 doesn’t matter if you don’t hit an organ you are a fool. To think that you don’t know more about ballistics and wound cavities and stopping power is embarrassing. I’m no gun nut but that’s bush league. Go back to your airsoft.

  • Nance, E

    Obviously hitting a vital isn’t the only thing to cause damage as they will put a hole anywhere. Your goal shouldn’t be to damage them however it should be to stop or kill them. The only reliable ways of doing this are vital hits. A CNS hit is the best as that will usually cease all action right away but a heart shot will stop them within after several seconds as long as it takes enough damage.

    The size really doesn’t matter if they don’t hit a vital. A .50BMG that is 14mms away from a vital will be less effective than a 5.56mm that hits a vital. Just as a 7.62mm that is 8mms away will be less effective thana 5.56mm that hits a vital. You get a hit to the arm with any small arms bullet and it wont make much of a difference as to the size. It isn’t something that can be counted on to stop them. A 7.62mm hole in non-vital areas is going to be just as ineffective as a 5.56mm hole in non-vital areas. Bigger bullets however allow for what would be misses with a smaller round to hit as long as they are within the difference between the two.

    Now rifle bullets usually have good temporary cavities but some organs are not that badly affected by this while others get torn apart by it. So the only reliable thing to go by is the hole left in a target. Which for 5.56mm bullets it is a 5.56mm hole and for 7.62mm bullets it is a 7.62mm hole.

    Some people can be stopped by getting shot in the finger, foot, or knee but this doesn’t mean shooting those areas is a good idea. You need to stop them from attacking you and the only ways to do so reliably are to hit the vitals. Ever been hunting? It is similar in some regards. When hunting you can’t just hit the animal in a non-vital area and expect it to stop or die. You get a bad hit and it will run. Now it might die from blood loss or infection but depending on the hit that can take hours for blood loss and days or weeks for infection.

    While hunting if you get a vital hit the animal may run a bit but it wont take long for it to stop as long as the vital took enough damage. Now if you were to hit a non-vital area it would run, unless what you do is shoot the legs I suppose, and you would most likely lose track of it. It might die eventually but it could also just recover. If it dies it will take at least one hour. In a self defense situation waiting even ten minutes for them to die or stop is bad. You need them stopping asap and as I said the most reliable way to do this is to hit the vitals. A CNS shot is the best but a heart shot can stop them after several seconds.

    Bigger bullets make things easier as the larger size increases the chances of a good hit but a bigger hole is secondary to where it is. If I had to defend myself I’d rather shoot the target in a vital organ with a 5.56mm bullet than hit a non-vital area with a 7.62mm or even a .50BMG. As I said some people will be stopped by even just getting hit in a finger but that doesn’t make it a reliable area to get them to stop nor does it make it a good place to aim. Hitting vitals isn’t going to always stop them right away but vitals hits do so more reliably than non-vital hits.

    Now a 7.62mm hole in a non-vital area will allow a slightly faster bleed out than a 5.56mm hole in a non-vital area but waiting for them to bleed out is a very very bad idea and can take a long time based on where the hit is. Which as I said is unacceptable for hunting and for defending yourself.

  • Nance, E
  • Frank

    Interesting!!! People in The year 2011 still talking about “stopping power”?? The term actually does not exist in ballistics!!! When looking at terminal ballistics, you want “maximum energy transfer” from the projectile to the target to produce “maximum incapacitation” effect.

    Huh?? Really?? Most GI’s cant hit a Tango at 10 yards if his life depended on it…. ok sorry that’s a bit harsh but you get my drift….

    The man needs all the help he can get to do as much damage as possible, though he wont hit a vital organ always, at least there’s gonna be some bad guy running to his mamma crying copiously and demoralizing his friends and family in the process… yeah yeah i know whatever!!!

    Severely wounding a terrorist will put a strain on bad guy central both physically and emotionally not even talking about money and man hours spent on rehab etc….

    So a larger caliber round has distinct advantages!!

    I don’t like the 7.62X51 , it’s phenomenal when talking about energy transfer, accuracy and penetration BUT you cant carry lots of it!! Mag capacity is limited etc…

    5.56?? good round also but in the African bush it tends to, sometimes, get pushed off course by a twig!!

    7.62 NATO and 30 BR sounds like a good idea!!! But we will have to see….

    6.5 Grendel round for intermediate ranges i.e. 300 plus meters GREAT my personal choice!!! It is obviously also very useful at shorter ranges. Great all rounder!!!
    6.8? Great idea for short range work, promising round, apparently has shown some good success in the field among contractors etc.

    Yeah yeah!! i can hear people scream contradiction!!! mag capacity!!! etc… deal with it!!!

    The only way to get the 5.56 NATO to perform is to contravene the Geneva conventions etc. and use the old “Black Talon” :-) I LOVE THAT BABY!!! Pity its difficult to get hold of today :-) Yeah range is easy to solve, just use a longer barrel!!!

    Now shall we forget that the good old German Wermacht used the 7.62X39 and then the Russians, to great effect??

    6 of the one and half a dozen of the other…..

    Last words??

    Use a modular rifle chambering 6.8 and 6.5. Short and longer range respectively.

    The rifle based upon (Yeah i know of the technical hurdles that can be overcome, by the way…)

    1. Tavor
    2. G36
    3. Remington ACR
    4. Galil

    NO M4!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

    It’s light and relatively easy to shoot and carry, BUT reliability in austere environments and asymmetrical combat, with no rules, i might add!!! i.e. no cease fire to clean the thing!!

    Well, there you have my opinion…..

    Any questions or queries and or disagreements? SORRY MANAGEMENT HAS LEFT THE BUILDING :-)

  • DonM

    The Germans did not use 7.62X39 against Russians, they did use a 7.92×33 against USSR.
    The Spanish used 7mm Mauser against US in 1898, and T. Roosevelt wrote about it. He noted that soldiers hit in the head, heart or spine died, and those not hit there recovered surprisingly quickly. There is a nervous reaction if you hit the spinal column, but that bit of tissue is small and easy to miss.

  • DonM

    Tactics: Don’t expect any single round to “stop”. Keep shooting until you see effect, even if you are shooting a .50 caliber. One fellow famously had a crowbar blown through his head, and didn’t lose conciousness, taking a horse drawn trolley to the hospital. The lasting effect on him was he swore and drank more. I would hope to drink and swear more if it happened to me.

  • DonM

    Others had RPGs and 40mm grenades blasted through the chest. Where it didn’t detonate there are cases where the fortunate soul survives.

    Not much point in selecting or arguing about the small difference in effect of 5.56/5.54/6.5/6.8/7/7.62, all can do execution, and all can miss, and be thus judged inadequate. Audie Murphy missed his first shot at a German, and convinced himself that it was the rifle’s fault, feeling that he had to so convince himself to continue to fight. He switched from a M-1 Carbine to a M-1 Garand after that.

    The big advantage of the 12 gauge 3 inch magnum with #1 shot is you get 25 each .30 caliber “through and through” penetrations for each round, and even then, there is a reason why they make these in double barrel configuration.

    Antoine Laurent Lavoisier, the discoverer of Oxygen was sent to the Guillotine during the French Terror. He demonstrated the ability to blink his eyes for 16 seconds after he head was severed. We don’t expect a single small bullet to have instant effect.

  • crappell


  • Infernal Lemon

    sooo… another m4? with crap you can get and put on yourself…. but built in? oh come on. why not something more exotic and new and awesome? why not just wait until caseless ammo is feasible for the entire army and use a gun that fires that?

  • I love reading these articles bceause they’re short but informative.

  • matt

    This only came out like a year ago AFTER the SCAR competition.

  • matt

    Ok to set this straight:
    1)this gun is more advanced than the SCAR which currently has no way of any kind of
    caliber conversion.
    2) Colt deserves no crap for the M4 being a DGI they tried to get the army to convert them (M4s) to OP RODS for years. The ARMY said no.
    3) Colt has been building OP ROD systems since the late sixties.

  • CavScout62

    It will NEVER happen.

  • CavScout62

    I feel the same way.

  • CavScout62

    Don’t be Silly, boy. LOL!!

  • CavScout62

    Right, we all know that the mag block adapter is going to be the 1st thing that is lost when the shite hits the fan! More extra junk from the Junk Kings @ Colt. As for the effectiveness of the 556X45, ya’ll are correct, it only took 100K rounds per dead NVA/VC during it’s 1st deployment. I know you are shaking your heads saying “NO WAY” but those are the real numbers my fello Veterans. 100 thousand rounds expended per enemy combatant killed in VietNam. Check the statistics for yourselves. Very effective COMBAT round, the 556X45, no doubt.

    • orly?

      That’s suppression tactics. Not hardware facts.

  • CavScout62

    I read the very same. I have also used the 6.8SPC and it is a very effective round for 0-500M work. You probably know it was developed by the 5thSF and Ronni Barrett at the request of the Brass who then said thanks, but no thanks. As for the HK 416, I would have done the same thing! it’s really sad that we have to use a German upper to get what we need when we are flooded right here at home with so much talent and excellent weapons. Procurement needs to be cleaned out and un-politicized.

  • IYD375

    JSOC SMUs are currently using HK416s as their preferred assault weapon. I very much doubt the CM901 was the weapon that killed bin Laden.

    Sorry to break it to the company.

    3rd Ranger Battalion

  • Infidel4LIFE

    I got a lil confused coz the man said you could swap out upper 7.62 for a 5.56. The 416 is being used by most US Spec Ops, and its prob the rifle that killed OBL. No doubt there were other weapons in use, but by whom? The MP-7 is a highly regarded weapon, and damn! i want one!! No joy on that 4 sure..

  • Infidel4LIFE

    Sorry fellas i got confused and i do believe Colt has some kind of “monopoly” going on. A piston would make every M-4 and M-16 more reliable. I don’t believe it was the Colt rifle that did the deed. Hell, i saw a pic of an operator carrying a CAR-15 all tricked out, short barrel no suppressor. Wat a great piece of gear he had. NICE.

  • Mark

    Hey we are getting cammo for the Joes in different environments, well lets get rifles for the Joes in different environments. Jungle and built up areas get the M-4 5.56, Desert, open country, high mountains get M-4 7.62. Then we dont have to have any more kinds of ammo. Of course we could go to the 7.62 x 39 or 7.92 x 33 or any of the other new calibers and really mess with the logistics.

  • Jeff Dulin

    This is all very nice but I saw this and some improvements 30 years ago on the AAR-18/180 by Armalite/Stoner. There, thay had eliminated the recoil buffer entirely by using two small oprods and drive springs on the to L&R of the receiver. They too had a gas rod driven system eliminating the origional sail-boat mess of the not ready for primetime M-16. The Mags needed work then too and the new ones are wonderful!


  • irobj

    And poorly trained draftees – praying and spraying…What a waste. All of it.

  • Avalanche

    Next I got to play with the show stealer. Colt Defense had brought out their new CM901. The CM901 is a very interesting idea in that it allows the shooter the option between 7.62×51 or 5.56mm with the simple switch of the upper. Chuck Olsen, project manager from Colt Defense had brought two version of the rifle. One was a standard looking M4, other than the lower and anodized Marine like digital camouflage pattern. He told me to first shoot the 5.56mm equipped CM901 and tell him what I thought. Handling it I noticed it was a true ambi-gun. All the control were full ambidextrous to include the safety selector, magazine release, as well as the bolt release. I really like the right hand side bolt release on the CM901. Unlike some of the other ambi-lowers I have tried before the bolt release was easy to use and didn’t require a huge amount of force with the trigger finger. The small by comparison 5.56mm Pmag locked home in the lower with zero play. Shooting the 5.56mm CM901 there was a noticeable difference. The rifle was very smooth in recoil, which is already close to non-exisitent in 5.56mm to begin with. I rang the steel target quickly and easily at 100 yards. After checking the rifle clear Chuck told me how they had redesigned the buffer assembly to work with both the 5.56mm round as well as the 7.62mm round and as a bi-product it is very smooth in 5.56mm. Colt had two rifles set up, both CM901s. Chuck said it was just to make it faster than changing uppers all day. Picking up the 7.62 version I was amazed at how light it was. The 13in barreled 7.62 battle rifle was equipped with the Elcan Specter DR 1-4x with the 762 reticle. The steel target down range didn’t stand a chance. The Colt’s recoil was smooth for a 7.62, especially for being as light as it is and with a 13in barrel. The recoil wasn’t much more than a 5.56 or 6.8, and up and to the right. I wish I would have had a Battle Comp BABC muzzle brake with me to have tried on it, but can see the two being a great couple. After a couple Magpul 308 Pmags I couldn’t stop smiling and could help but ask when would this thing be available for me to buy. I have been saying for some time how I want a battle rifle and the CM901 is high up on the list of potential purchases. When Nona’s, our local Italian restaurant had shown up with chow, all the vendors bolted for food and I was put on weapons guard detail. Chuck from Colt stayed out with me and we talked about guns and more so about bullets. Chuck opened my eyes on a few things and discussed Colt’s military weapons with me. Chuck is a **** of a guy and I hope I get the chance to talk with him again as well as shoot the CM901.

  • MTNpatrol

    PISTON VERSION please!
    My God, can you imagine the carbon buildup on a 7.62 direct impingement bolt and action after 5 or 6 magazines??
    And then there’s the heat that direct impingement gas would create. “Cook-off” anyone?

    Just scrap the AR rifles and go to an FN SCAR design (NON-recip. bolt version) or an ACR from Remington Defense.

    And THEN make it in 6,5 Grendel or 6.8 SPC. 5.56 doesn’t cut it.