Colt Canada’s new Modular Rail Rifle is the follow on to their Integrated Upper Receiver which relies upon Picatinny Rails at the fore end. Users found the hand guard to be too bulky for a proper grip and Colt Canada wanted to adopt a more attachment standard. They chose M-Lok for the MRR.
Here, you can see the single construction of the upper receiver and hand guard.
It’s available in three calibers, 300 blk, 5.56mm, and 7.62mm. The 7.62mm is based on the Colt 901 lower receiver.
They come standard with an improved chamber over the IUR, continuous integral top Pic rail, and a free floating, chromed hammer forged barrel. Additionally, Colt Canada offers ambidextrous controls for the MRR and various coated it anodized finishes.
Tags: Colt Canada
The IUR/MRR is an astoundingly good design. It continues to boggle my mind that Colt USA hasn’t snagged it for distribution/sale here in the US yet.
Question for anyone who has handled one of these, or used them long term- by what manner are you able to clean the barrel under the handguards? I am not concerned about silly “inspection” cleaning, but long term after mud/salt water/general grime etc. How do you prevent rust essentially?
I’m guessing you shoot the barrel out before the rust reaches the bore.
In all seriousness, I’d probably just stuff a lightly oiled rag on the end of a cleaning rod, swirl it around the barrel every few cleanings, and call it a day.
If you’re concerned about such things Colt Canada has a barrel wrench available for armorers. The barrel is incredibly easy to remove with the right tools.
If you’re just doing operator maintenance, and you’re working around salt, hit it with a fresh water bath and then apply oil with a spray bottle. There’s not a lot of room to slide a rag down the handguard.
I have a Colt MARC 901 and the lower rail removes for cleaning / rail maintenance, I suspect those small holes on the rail are a release mechanism for the hand-guard.
There is no lower handguard release – it’s a solid monolithic upper.
Falcon is correct. There is a lower half heat shield in the IURs which I would imagine is also present in the MRR. Getting into the tight spaces is a legitimate concern, but as noted a spray will probably get the job done.
Given the intended market is exclusively military sales the lack of user serviceability (CC doesn’t sell the tools to remove the barrel to civilians) isn’t really a surprise.
I wonder what this improved chamber over the IUR is about?
I love me a Colt 901, that M-LOK upper with 18″ barrel would be a great update for the 901, though I doubt Colt will ever bring it to US.
“Modular Rail Rifle” is how I will refer to all AR15 style rifles from now on.
The “EH-R 15”?
This guy fucks.
So they’ve solved their issues getting .300BLK to run reliably?
I believe the 300BO is very new and only available in an 8.5” shorty.
Colt Canada also exclusively runs carbine length gas on the 5.56 guns but they are said to have tuned the operation to eliminate bolt bounce via high speed video analysis. Since they don’t, to my knowledge, change uppers between contract and civvy sales I would imagine the tuning is for NATO rounds.
Just picked up a 10.5” UK SF upper and it is a piece of art, but as noted, the integral pic rails do make grip positions limited.
Hadn’t heard about an improved chamber either. Not sure what that’s referring to.
Is that UK SF 10.5” in 5.56mm?
It is. It’s also a 10” barrel not 10.5” – I love mine, but the recoil is a little rough.
Yes it is. I’ve seen it reported as 10” and 10.5” and never bothered to measure. The CC box had been seen stamped 10.5, hence the confusion.
It is sporty on the recoil front. I’d love to try the 11.6” MRR.
Nice. Had heard that their .300BLK was not ready for prime time for some reason related to “reliability”. *shrug*
As was with the LMT MRS back in the day, the question however outdated it seems is still a query I can’t get my head around-not that I am criticizing.
When you smear a section of rail, deform the rail with the use of a modular addition or just plain have a full gravity event like a PLF turned belly flop is the answer to replace the entire upper?
Seems like a true answer to some bigger issues, it’s the accumulation of the smaller ones has me a tad questioning here.