Review: Colt Canada IUR – C8 Integrated Upper Receiver

Colt Canada IUR

Around this time last year, the first IURs were made available to Canadian civilian shooters. After that initial limited offering, a number of “blemished” units returned to Canada in the fall of 2015 as overrun from a Colt Canada military contract. I bought one, and have been having a great time shooting it:

Correction: The C9 LMG is made by FN, not Colt Canada. The C9A1 to C9A2 upgrade was performed by Colt Canada.

If you’re already familiar with Colt Canada, and just want to read about this particular IUR, feel free to scroll down to the review portion just after the photo of the rifle resting on the ground.

For those of you who are unfamiliar, Colt Canada was formerly Deimaco, is a subsidiary of Colt LLC, and provides all the rifles used by the Canadian Forces. In addition to the C7 and C8 programs, Colt Canada also manufactures rifles for a number of other NATO armies. Notably they’ve seen widespread adoption by UK Special Forces, as well as being issued to the Danish and Dutch armies.


The UK’s version of the C8 IUR is identified as the L119A2 and issued to a multitude of Special Forces groups.

The IUR program is part of a long evolution of Canadian rifles. The initial C7 in 1984 would feel very familiar to a US Marine trained on the M16A2. But the C7A1 and C7A2 rifles used by the Canadian forces today are flattop rifles with a 3.4x Elcan C79 optic on top. The C7A2 introduced ambidextrous controls, green furniture, and a 6 position collapsible buttstock similar to that used on the US M4. A compact 15.7″ carbine was named the C8, which is what the UK Special Forces generally carry.

Rather than adopt an RAS quad rail system like the United States, the C7A2 and C8A2 were outfitted with a front-sight-base Tri-Rail for accessories, eventually leading to the IUR. The forward Tri-Rail is still the most common method of mounting IR lasers in the Canadian Forces, but Colt Canada has been marketing their IUR as an armory level upgrade to their various customers.

IUR stands for Integrated Upper Receiver, more commonly known as a monolithic upper receiver. The idea is that with a single unified rail the barrel can be free-floated, and any accessories like lasers and night vision will hold zero regardless of their placement.

Both Denmark and the Netherlands have bought and issued IURs to their infantry units, and the uppers made available in Canada are overruns from one of those contracts. The internet scuttlebutt I read seems to suggest that they’re Danish, based on the 40mm recoil launcher lug on the bottom and reduced side rails. However I have to confess that I’ve been unable to find any photographs of any NATO army using the exact IUR configuration I’ve got in my safe. The majority currently in the hands of Dutch and Danish soldiers seem to be full quad rail models, and usually feature a folding front sight base.


A Danish soldier carries his IUR during a NATO training exercise. Note the folding front sight and full length rail, different from the author’s rifle. However the C9 flash hider is clearly visible underneath the BFA.

Regardless of their specific origin, the IURs have seen a burst of popularity in the Canadian shooting community. While the initial uppers were $1100, the “blemished” units that had been shipped back and forth across the Atlantic were retailing for a remarkably low $550 at retailers across the country. Interestingly, none of the IURs available in Canada have included a bolt carrier group or charging handle. That falls to the individual user to buy.

The author's IUR out on the Alberta prairie. This configuration uses a lower from another Canadian manufacturer NEA, and was not a very tight fit.

The author’s IUR out on the Alberta prairie. This configuration uses a lower from another Canadian manufacturer NEA, and was not a very tight fit.

I bought my IUR not just out of a Canadian loyalty and desire for limited edition firearms, but also as a heck of a deal on a monolithic receiver with a cold hammer forged barrel and milspec flash hider. Mounted on an NEA lower, I was producing groups in and around the 2MOA mark with 62gr M855 green tip ammunition. The expectation is that this rifle should shoot a little better than that, so I set out to find an approved lower to see what we could produce. Colt Canada of course encourages you to mount the IUR on a C7 or C8 lower, but to pickup a completed semi-auto CC lower right now is anywhere from $900-1300. While I love ambi controls and Canadian-made goodness, that is just way more than I can justify spending on a milspec lower.

O’Dell Engineering, the distributor of civilian Colt Canada products, does have a few suggestions for lowers, which included the American Tactical Imports Omni lowers. I think it’s fair to say that most shooters are skeptical of polymer AR-15 lowers, myself included, but at $100 I couldn’t argue with the price point, particularly when the official word was that they should produce a tight fit and groups.

Colt Canada IUR & ATI Omni Lower

The author’s IUR paired with an ATI Omni polymer lower. Perhaps surprisingly, this recommended lower was a much tighter fit and produced tighter groups.

Sure enough, I had to gently hammer the IUR onto the Omni lower, and it showed a difference on the range. Using Swiss 63 grain RUAG 5.56 ammo my best 5 shot group was 1.3 MOA, and my best 3 shot group was 0.49 MOA, a substantial improvement over my initial trials. Interestingly the heavier 77 grain and 69 grain loads I tried shot terribly out of the IUR’s 1:7 barrel twist. I couldn’t get a group under 4 MOA with those weighty bullets.

The barrel inside the IUR is attached via a proprietary Colt Canada mount, but with the right tools it can be a quick change system. Remember these are rifles designed for amourer level servicing rather than individual tinkering.

The gas system is a standard direct impingement setup, but it does feature a straight profile gas tube underneath the handguard. The barrel is heavy profile right up to the gas block, then medium profile from there to the muzzle.

All IURs ship with an unusual muzzle device. The C9 conical flash hider was developed for the Canadian Forces C9A2 light machine gun, to improve full auto handling over the C9A1. The only way to own one at the moment is to buy an IUR. It’s designed to be a step up from the A2 muzzle device with a combination of moderate braking ability and superior flash suppression. I have to confess that I haven’t shot the IUR under NODs yet. The short days in Canada are paired with extremely cold nights. But on an evening shoot where my 10.5″ AR with a standard A2 produced plenty of flash, the IUR & C9 did not.

C9A1 Light Machine Gun

Author’s photo of the original C9A1 LMG in service with Canadian Forces Reserves, notice the birdcage style flash hider.

There are two major criticisms to be leveled at the IUR, the  weight and the grip. At 4lbs 15 oz oz the completed upper means you’re looking at a 9lb 7oz rifle in my case. Not terrible, but a chunk more than your conventional 7lb M4 carbine.

The other odd point comes from the grip. Depending on a shooter’s hand size and grip the elevated QD sling slots built into the IUR can end up right underneath your palm. I found this personally puzzling as it does seem like the 3 o’clock and 9 o’clock rails have been reduced intentionally to offer a dedicated (if small) holding space.

While the initial run of IURs were $1100, the blemished units that blew out at $550 have all but disappeared. I suspect that in a year or two the original IURs will all be gone, largely replaced by the new Modular Railed Rifle or MRR that was announced in December 2015.

These new M-LOK rifles are marketed as the evolution of the IUR line, and will be available in numerous barrel lengths for military and Canadian civilian customers. By replacing the hand-guard picatinny with M-LOK, Colt Canada says they’ve reduced the overall weight by at least a half a pound between comparable rifles. From what I felt shouldering the MRR rifle at Shot Show last month, it feels more like a full pound less up front.

Close up of the monolithic M-LOK fore end of the MRR.

Close up of the monolithic M-LOK fore end of the MRR taken at Shot Show 2016 in Las Vegas.

While the MRR might represent the future of the platform, I’m quite happy to have snagged my IUR for a reasonably good price. Beyond the pure nostalgia value of a limited run Canadian-made rifle, its also a hell of a shooter and a welcome addition to the gun safe.

Colt Canada MRR Modular Railed Rifle

Edward O

Edward is a Canadian gun owner and target shooter with a Bachelor’s Degree in Journalism. Crawling over mountains with tactical gear is his idea of fun. He blogs at TV-Presspass and tweets @TV_PressPass.


  • Evan

    I didn’t know ARs were legal in Canada at all. Especially not with what looks like a standard capacity magazine.

    • kgallerno

      AR’s are legal here for the time being. Unfortunately they are restricted to range use only. All semi auto rifles in Canada are restricted to 5 rounds for the magazine. As such we can have thirty round or drum mags. But they are all pinned to 5.

      There are workarounds for our magazine capacity laws since they are poorly written. For instance pistol mags are restrited to 10 rounds for the caliber they are designed for. So we can for instance load 13 rounds of 9mm in a Beretta 96, .40 cal magazine and use it in a Beretta 92 legally. This is what i do.

      This workaround also allows us to load up up 14 rounds of .223 in a .50 cal Beuwolf rifle magazine as long as the magazine itself is pinned not to hold more then 5 Beuwolf rounds.

      Pistol mags can also be used in rifles giving us up to 10 rounds in a rifle. Lar 15 magazines would be a example of this.

      • Evan

        So range use only means you can’t use an AR for home defense, or take it to the woods or whatever? Ridiculous. And the magazine capacity laws are absurd too. Do you have to own a .50 Beowulf rifle to load a “.50 Beowulf” mag with 14 rounds of 5.56? It’s the same mag, how does one determine whether it’s a .50 Beowulf mag or a regular 5.56 mag? If someone made an AR pistol in .50 Beowulf, would you be able to load 10 of those rounds or 30 5.56? Would it be legal for you to take a regular 30 round AR mag, claim it was designed for a .50 Beowulf pistol, and load it with 30 rounds anyway? And I thought American gun laws were dumb.

        • The_Champ

          Basically yes to your range use question. A restricted firearm in Canada (all pistols, AR’s, certain rifles of less than a certain length, etc) can only be used at an approved range, and have stricter transportation and storage rules. Ie, in a locked box with a trigger guard, and transported only directly to your range then back home again.
          But, I can toss a Remington 870 in my trunk, no trigger lock, and drive around all day, stomp around with it in the woods, etc. Go figure.

          A VZ58 or Mini-14 or BAR in .300 wing mag are all non restricted, but an M1 carbine IS restricted by virtue of its barrel being a few millimeters short of the cut off. And any and all AR rifles, regardless of length are restricted, because they are scary I guess.

          I think gun laws EVERYWHERE feature absurd rules that make sense only to legislators who have zero experience with firearms.

          • Evan

            Ugh that sounds awful. I imagine trying to buy guns is a real dog and pony show up there too. Are these laws federal? Can you just move to another province where the laws are less nuts or are you pretty much stuck anywhere in the country? Cause I’m from New York, and due to the absurd gun laws (and countless other reasons) I left NY and moved to Pennsylvania, where gun laws are normal.

          • kgallerno

            Gun laws are Federal. They are the same for each province with very minor differences at the provincial level.

            Buying firearms is easy enough depending on class. Non restricted rifles you can buy and walk out of the store with it in your hands after showing your valid firearms license. Most shotguns, hunting rifles, some black and red qualify as non restricted.

            Restricted class firearms are still easy to get as well. You pay for them. At this point the shop or the seller contacts the RCMP to inform them you are taking posession of said firearm. The RCMP has to aprove the transfer before said firearm is actualy transfered. Transaction time is ually less then a week. You ofcourse have to have the apropriate license to aquire a restricted firearm. All hand guns with a barrel longer then 4.2″, some black rifles, some red rifles and all semi auto, center fire rifles with a barrel shorter then 18.5″ are restricted.

            Aquiring a restricted license is easy enough to do. Just takes a few months for the RCMP to do their due dilligance in their checks on the applicant.

          • Evan

            What counts as prohibited? I gather that AKs are prohibited, but what else? Is it just an arbitrary list of named guns?

          • The_Champ

            There is an arbitrary list as well as full auto and small sized pistols of certain calibers and barrel lengths.

          • kgallerno

            There is a named list of prohib guns. It is pretty extensive. Pistols with barrels shorter then 4.2 inches and certain calibers are prohib. As are all full auto rifles. But there are still a couple of them kicking around thanks to grandfathering. They cant leave the safe though.

            In the 90ies we had a sweeping reform of firearms laws after a school masacre here. The powers that be at that time decided to prohibit all scary rifles. In order to choose what guns to prohibit the idiot politicians found a copy of a gun magazine and circled every scary black rifle in it for prohibition. Pretty much any black rifle or red rifle around in the early 90ies went prohib for us. It is only by well fought battle we kept the AR15 off the named list.

            In this magazine was a article on a new firearm HK was designing. This firearm was made prohib even though this gun never made it past the design stage or even left the factory. Yes this is how stupid our laws are. We prohibited a rifle that was never commercialy manufactured. I wish i could think of its name. Im sure someone will chime in with it.

          • Evan

            Was it the G11? I think that’s what it’s called, the one that fired caseless ammo. Either way, that’s monumentally stupid. Fortunately, they haven’t managed to ram that idiocy through here.

          • The G11 was the HK caseless rifle.

          • “Red rifles” = commie guns?

          • kgallerno


          • Weird. I’ve always heard them lumped in with black guns.

          • kgallerno

            Must be a Canada thing. Eh.

          • FarmerB

            Handguns LONGER than 4.2 inches are restricted? Is that right?

          • kgallerno

            Yes. Restricted means we can own and use them only at government approved ranges. There is storage and transportation requirements for owning restricteds.

            Handgun barrels must be longer then 4.2 inches in order to be restricted. Anything under 4.2 inches makes it a prohibited.

          • FarmerB

            Ahh, thanks – that makes sense. Shorter is even MORE restricted.

          • Yep, those Canadian gun laws are Federal-level, and they make American laws look sane. Well, except for our suppressor law.

          • The_Champ

            I don’t know, your rules around your SBR’s and products like the sig brace seem pretty insane to me ?

            FYI suppressors are completely prohibited here.

          • SBRs are actually a byproduct of a major bullet we dodged. You’re familiar with the National Firearms Act (NFA), which established the registry for machine guns, suppressors, SBRs and SBSes, right?

            Well, originally, pistols were going to be NFA items, but that part of the draft got removed. SBRs/SBSs were just a loophole closure for that.

        • 1leggeddog

          “So range use only means you can’t use an AR for home defense”

          Home defense? What’s that?
          Oh you mean the right to defend yourself in your own home ?

          Naaa we don’t have that.

          No really, we don’t.

  • john huscio

    Are colt Canada uppers importable? Seems like they might be as they aren’t firearms.

  • ARCNA442

    Three and five shot groups? 77gr (presumably match) bullets getting 4 MOA in a 1/7 twist barrel while M855 is getting 2 MOA? It is past time to introduce the standardized accuracy review that was mentioned awhile back.

    • Keep in mind that Canadians can only own 5 round mags.

      • ARCNA442

        If there is an ammunition limit than it would be understandable, but not wanting to reload doesn’t make a 5 shot (much less a 3 shot) group statistically significant.

        I enjoy the rigor of the Firearm Blog compared to most other gun blogs (some of your recent articles about the AK-74 and 5.45×39 have been amazing), so please take this as constructive criticism. But if accuracy is going to be mentioned, how hard would it be to just always include a picture of a ten shot group at 100 yards / meters?

        • That’s up to Ed to address, I am just saying that there are magazine limits involved.

          I mean, I usually shoot 10 shot groups, but as you’ll see tomorrow in my M1 review I occasionally make exceptions due to magazine capacity restrictions.

          • Pat

            10-shot magazines are legal and available to use in AR-15s up here.

            I’m not sure why the author used M855 for one accuracy test using the NEA lower and then switched to a different brand and load for the second test on the ATI lower. This, I would think, would render any comparison between the two lowers irrelevant.

            I second ARCNA442’s request for an accuracy testing standard on TFB articles.

      • 1leggeddog

        We can use LAR-15 mags for 10 round capacities. We can even use .50 Beowulf Mag to up that to like 17 or 18 rounds of .223 but ssssssh. dont tell anyone!

        • Joshua

          not anymore…

          • 1leggeddog

            what? Yeah we can still use thosee mags unless something has changed recently that i am unaware of…

          • Joshua

            there was a letter from last November that was sent by RCMP to a importer of Beowulf magazines, which said that they would no longer be able to import them as they were originally designed to feed 5.56x45mm and merely modified to feed .50 Beowulf, and that since the ability to feed 5.56x45mm was not deleted, that it qualified as a 14 round 5.56x45mm magazine, and henceforth would be considered prohibited. as far as I know that letter still stands as law. I will try and find some source materiel and post it in a follow-up

          • 1leggeddog

            Ah so it could only apply to these mags specifically, while legit .50 Beowulf mags should still be good.

  • H&R Canada

    I have my Iur mounted on a norinco lower, fits and shoots well but man it’s a chunk of steel. With my red dot that sucker gotta be 10lbs

  • WT

    Does anyone have an insight as to how these are manufactured?
    Are they a signle forged blank and then machined?
    Or cnc machined from signle billet?
    Or 2 pieces, machined and then welded/bonded together?

  • tads

    nice write up. does your rifle have the “dutch chamber”? Apparently, the c8 chf chamber was tapered at the dutch gov’ts request after some reliability issues, and this is supposed to smooth out pressures in a 16″ barrel with a carbine system.

  • The_Champ

    “Our courts and police despise us using firearms for defense even though it is legal to do so. They will go out of their way charge most times any ways to punish a user finacially through the court process even though they stand little chance of conviction”

    I would respectfully disagree with the above. I know there have been a few high profile cases you are likely referring to, but they are few and far between. To say police despise citizens defending themselves, I think, is a giant hyperbole and incorrect.

  • CavScout

    Pointless. So far the only system I’ve seen that uses monolithic upper practically and to the fullest extent is the LMT MRP system. You can quickly swap barrels, calibers, between DI and piston, etc. Colt did it, kinda, and you can’t ever swap the barrel, and the pinned folding front sight isn’t on the solid top rail… Then with the ACR and SCAR, they just have next to no options thanks to the quick change barrel systems. All useless.