BCM® Mk 12 Complete Upper Receiver Group Mod 4X-Bravo (KMR-A15)

MSRP: $1,396.86
Your Price: $1,151.86
(You save $245.00 )
Maximum Purchase:
5 units
M4 Feed Ramp Barrel Extension
5.56 NATO
Barrel Style:
Barrel Length:
Stock Status:

Out of stock

About the BCM® Mk 12 Complete Upper Receiver, Mod 4X-Bravo (KMR-A15)

Features included in basic price:

  • BCM® KMR Alpha 15"
  • BCM® SS410 18" Stainless Barrel, Ionbond Black DLC
  • Rifle Length Gas System
  • Pinned Low Profile Gas Block
  • BCM® Bolt Carrier Group (HPT/MPI), auto

Optional Features

  • Optional Muzzle Devices: A2 Flash Hider, BCM Comp Mod 0, BCM Comp Mod 2, BCM Comp Mod 4, BCM Comp Mod 6, PWS FSC556 Comp Mod 2, AE MK12 Comp, SureFire SFMB 556, SureFire Warcomp Closed Tine Flash Hider 556, SureFire Warcomp Flash Hider 556.
  • Optional Charging Handles: No Charging Handle, BCM® Mod 3B (LARGE Latch), BCM® Mod 4B (MEDIUM Latch)

More about this complete upper group

The United States Navy Mark 12 Mod 0/1 Special Purpose Rifle (SPR) is a rifle that has been in service with the United States special forces in Operation Enduring Freedom and Operation Iraqi Freedom. SPR initially stood for Special Purpose Receiver, but that nomenclature seems to have disappeared as the weapon became a stand alone weapon system, and not just an add on upper as part of proposed SOPMOD upgrades. SPR now means Special Purpose Rifle. It was eventually type classified by the Navy as the Mk 12, though the Army also uses this designation.
This weapon system, used by Special Forces units of both the US Army and US Navy, is a heavily modified deviation from the familiar AR15/M16 line of infantry weapons, and thus is chambered for NATO standard 5.56 x 45 mm caliber ammunition. It serves a light sniper/designated marksman role. The SPR was originally proposed by Mark Westrom, currently president of Armalite, while at the Rock Island Arsenal. The SPR program was an outgrowth of the desire by both US Army and Navy special forces for a rifle with greater effective range than an M4 type Carbine but still shorter in length than a standard issue M16A2/A4. The SPR program appears to have grown out of both the SOPMOD Block II program, and the U.S. Navy SEALs 'Recon Rifle' (a 16" flat-topped AR-15/M16 Carbine).

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***This product contains chemicals/materials known to the State of California to cause cancer and other reproductive harm. To learn more, visit www.p65warnings.ca.gov.***

12 Reviews

  • 5
    A work of machining art

    As a machininst the first thing I noticed was the absolute flawless machining and assembly of this upper. I could hardly wait to get to the range to test the workmanship of this product. After a thorough cleaning and inspection I decided to use an ACOG (TAO1NSN) 4x I had on hand and mounted and torqued it to specs. I went to my club range and sighted in with Geco 55 gr 5.56 ammo. Once sighted in I proceeded do break- in by expending 100 rounds doing spot drills at 7 yds, and groups at 100 and 300 yds. Groups hovered at moa without a single hiccup, malfunction, or failure of any type. I then proceeded on to my favorite match load of Sierra 69 gr match at 300 yds. I was able to print sub moa groups effortlessly with a 4x power optic. Needless to say this will probably become my favorite AR. Cleaning after 150 rounds was easy with no real build up of copper or powder fouling. I can't wait to get it on the 600 yd line. Money well spent! Thanks BCM!

  • 5
    sub moa

    I purchased this complete upper two months ago and couldn't be more impressed. I also bought a BCM lower from Ranier as BCM had none in stock. Fit and finish are superb. I have only fed it American Eagle 223 55gn for barrel break in then switched to some "budget" PMC xtac match 77gn otm to get an idea of the rifle's accuracy potential. First/only group measured 3/4" at 100yds. Unfortunately I had to quit for the day after that. This was off sandbags sitting on a relatively unstable bench. I look forward to testing this and other ammunition from the concrete bench at my range. Recoil was minimal (even for an AR). I'm sure the rifle length gas contributed to that. Thank you BCM.

  • 5
    Great upper for the price.

    The upper shoots really well, have a viper pst 1-4 on top of it and with 55gr pmc FMJ keeps a group of 1 moa at 100yds and holds a 1/2 moa with 75gr bthp Hornady. Loving the upper

  • 5
    Outstanding quality!

    This is not my first BCM product and will not be my last. A great American company producing a great American product! What's not to love!

  • 5
    Amazing upper!

    Amazing shooter! Shoots one ragged hole at 100 yards. Runs flawlessly.

  • 5
    Excellent product

    I am very Pleased to say the BCM has far exceeded my expectation. The product quality is well made and looks amazing. I've gone back and bought 2 more uppers since writing this.

  • 5
    A mighty fine spr upper

    Very pleased with this upper, fast shipping, clean our of the box, zeroed in no time. VERY accurate barrel and you can't beat the keymod rail.

  • 5
    Excellent upper assembly

    Fit, finish, weight, and accuracy are all outstanding. Plopped it on a S&W lower I had lying around, added a Magpul fixed MOE rifle stock, a Geissele SD-E trigger, a bipod, and a Vortex Viper PST 2.5-10x32 scope, and was grouping 223 Winchester Ranger BTHP Match 69 gr under 1" at 100 yds while zeroing the scope.

    Probably didn't have to break in the barrel, but I did anyway - 5x1 shot cycles / 1x3 shot cycle / 1x5 shot cycle.

  • 5

    I have always wanted to put together a MK12 and there was no other brand I wanted than BCM. I can confidently say that I'm not disappointed, not only is this product well manufactured but it performs great on paper too! Thanks for such an amazing product!