Colt Introduces New Upper Receiver Kits

Colt is now selling upper receiver kits in various lengths. From the press release:

WEST HARTFORD, Conn. (May 8, 2014) – Colt’s Manufacturing Company, one
of the world’s leading designers, developers and manufacturers of
firearms, is now offering complete upper receiver assembly kits in a
variety of barrel lengths and configurations. The conversion kits are
derived from the popular LE6920 and LE6940 models, offering the
standard upper receiver with handguard configuration and the
monolithic one-piece receiver with free-floating barrel configuration.
Three upper assembly models come in the traditional 16.1-inch barrel
length, and for the first time, two upper assemblies are available in
the shorter 14.5-inch barrel length.

“The upper assembly conversion kits will allow us to offer more
high-quality, state-of-the-art choices to our customers,” said Joyce
Rubino, Vice President of Marketing for Colt’s Manufacturing. “The
upper assemblies are made to the same military specifications and are
subject to the same rigorous testing processes as every rifle that
comes off our line.”

All kits are ready to mount to a complete Colt lower receiver and
include a charging handle and a complete bolt carrier group with a
properly head-spaced bolt. Other features of the upper assemblies
include chrome-lined bolt carriers and barrels, with 1/7 right hand
twist barrel rifling. Each of the upper assemblies also comes with a
back-up rear sight. One model, the LE6920SCMCK, features a Troy rail.

An added benefit of the upper receiver assermbly kits is that they can
be used with any and all Colt lower receivers. Kits will all ship with
an adapter screw so that the uppers can attach to Colt models with
large pivot pins (.315” diameter).

The upper assembly kits will be available in Colt’s web store and at
local retailers. The MSRP will range from $740 – $1,056.

I doubt Colt will have any trouble selling them.

Nathaniel F

Nathaniel is a history enthusiast and firearms hobbyist whose primary interest lies in military small arms technological developments beginning with the smokeless powder era. In addition to contributing to The Firearm Blog, he runs 196,800 Revolutions Per Minute, a blog devoted to modern small arms design and theory. He is also the author of the original web serial Heartblood, which is being updated and edited regularly. He can be reached via email at


  • Bubba

    Do these have M16 carriers or do they have the AR-15 carriers that won’t work with an auto sear?

    • Geodkyt

      You know, given the cost of a decent full weight carrier compared to the cost of the upper, I really don’t care — if it has a gelded carrier, I’ll GunBroker that bad boy and have a new carrier installed in the gun before the auction even ends.

      • Geodkyt

        However, I can’t imagine paying the price for the “glory” of having a Colt marked upper, when I can assemble my own upper from equal quality parts (selected piece by piece for my specific wants and needs) cheaper, and without the silly M4 profile barrel.

    • 556m16

      They are equipped with a full auto carrier, there is a note that the BCG won’t work with a lower with a sear block.
      The upper also has a sear cut-out on the upper & would fire full auto with a properly registered NFA automatic lower receiver.

  • Chris

    HK 416 looks without the reliability or accuracy and almost the same price.

    • LCON

      Not even, HK416 uses a proprietary monolithic rail system that mounts without need of the ring mounts.also the front sight on HK416 folds forward this folds back

      • TCBA_Joe

        Actually, the 416 rail isn’t monolithic. However, the 2 uppers on the bottom of the ad above ARE monolithic.

        That said, the Colt’s really are very reliable. Granted they look nothing alike.

    • Rusty Shackleford

      Colt’s uppers are pretty underwhelming since you could buy all sorts of different configuration AR15 uppers complete with FNH CHF barrels from Palmetto State Armory for relatively cheap yet equal quality, but HK sells the MR556 upper for $2300 and the lower is another $1000! Personally, I’d like to see a torture test of the MR223 vs Core15 with an Adams Arms kit.

      • Chris

        As much as I’d like to see a MR233 and a Franken FN AR-15 duke it out. One party is going to contest the results regardless.

    • Andy

      Not even close to the same price. The HK upper is about twice as much.

  • Dan-O

    Late to the party and underwhelmed Colt, bravo. {insert slow clap}

    • Yellow Devil

      Let me help you out there.

    • All carbine-length gas systems and handguards. Thanks, but I’ll pass.

  • hod0r

    ugh, why the stupid M203 cut?

    • ColaBox

      What’s wrong with it?

      • Anonymoose

        I’d much rather see the 6940s with 16″ hbars. There is no reason to have an M203 cut when the forend is part of the receiver.

      • hod0r

        What isn’t wrong with a cut on the barrel that serves no purpose? Mind if i cut your other guns’ barrels a bit here and there?

        • ColaBox

          I don’t know, it serves a purpose if your trying to replicate an m4a1. Before I discovered free floating I had my AR in standard furniture and the cut helped with the replication. I mean that point is moot now…but it still looks second kind of cool. Its not like it hurts.

  • Steve_7

    Make them with a 1/9 twist and I might buy one.

    • Rusty Shackleford

      Or, at the very least a 1×8 twist.

    • You LIKE being restricted to bullets under 70 grains?

      • Rusty Shackleford

        No, that’s why I prefer the 1×8 twist. It gives you the better accuracy when firing 55 gr and 62 gr bullets like the 1×9, yet can handle both M856 tracer AND 77gr for the long shots like the 1×7.

      • Steve_7

        As I recall even 85-90 gr bullets only require a 1/7.7 twist or thereabouts. I’ve shot 75gr bullets through a 1/9 twist, worked fine. And frankly I very rarely use bullets heavier than 69gr and if I was going to, I wouldn’t use a Colt barrel with a standard chamber. 1/7 twists are silly, they’re just less accurate, even Colt’s recommended a 1/9 twist. There’s a good article about it actually in the June issue of American Rifleman.

        • JumpIf NotZero

          … Find me an 85 and 90gr round that fits OAL in an AR magazine. I’m very skeptical you are really aware of what you’re talking about.

          • Steve_7

            I’m totally aware of what I’m talking about – that was my point, 1/7 twists are useless. Like you say, you can’t fit them in the magazine so what is the point? And that AR article was written by John Plaster, who certainly knows what he is talking about.

          • JumpIf NotZero


            You should let LITERALLY everyone know they are wrong! Like every high quality AR mfg, ammo mfg, and shooter for the last 60 years know that 1/9 twist is ideal for 5.56. I’m sure Colt, BCM, Noveske, LMT, KAC, DD, HK, SIG, Remington, and EVERYONE ELSE would love to see that! Everyone is wrong @Steve_7:disqus and a gun rag he read is right.

            You should frame that American Rifleman issue. June was it? It’s going to be worth a ton as a collector’s item in years, when it will be recalled as the issue that changed everything we know about ballistic coefficients and bullet stability.

            Ha, 90gr 556!

          • Steve_7

            Colt’s _themselves_ recommended 1/9 for 5.56mm. The reason for 1/7 was because it was developed for the FN Minimi, for the purpose of using tracer, aka SS110. These are facts. There’s no point to it for target shooters unless you’re using really long bullets which as you say don’t fit in the magazine. It’s a well-known fact researched thoroughly by the US Army that M855/SS109 ball out of a 1/7 twist is not as accurate as it is in a 1/9 twist, the reason they used 1/7 was so that M856 tracer could be used in the rifle.

        • It depends on the air density. On a warm summer day, 1/9 or 1/8 may be adequate for 75 and 77 grain bullets, but on a cold day, your groups might open up.

          My 1/7 twist barrel actually shows a slight preference for 55 grain bullets, oddly enough.

          • Steve_7

            Well where I live it is not a warm climate, but at the end of the day it’s about bullet length rather than bullet weight. With a standard Colt barrel you’re not likely to be using anything terribly exotic given the chamber, especially if it’s a 16 inch barrel. I don’t know too many people shooting 77gr Federal GM for example through a 16 inch barrel (well, who don’t work for the USG). Even if a 1/7 twist barrel worked better with those (which I don’t think it does), for regular 55gr, 62gr, 69gr etc. sort of stuff, 1/7 is totally pointless. I had a Colt LW Sporter with a 1/7 twist as I recall that was also accurate with 55gr bullets, those rifles for some reason have a good reputation for accuracy, tighter chamber? No idea, but Colt used to hand select 1/7 barrels for the Delta HBAR which were also accurate. However all things being equal, 1/9 should be more accurate generally with common ammunition types.

  • JT

    All I remember was wanting a Colt AR decades ago for a sane price and Colt going **** you