ADM 18″ UIC MOD 2 Upper Receiver: Dialing-In the Long Yard

Initially introduced at SHOT Show in 2014, the Universal Improved Carbine (UIC) MOD 2 by American Defense Manufacturing (ADM), continues to be the mainstay of the UIC line of rifles, and comes available up to an 18” barrel length (featured in this review) and others. ADM continues to work at bringing its greatest level of manufacturing to the UIC MOD 2 line, and the 18” barrel reflects its goal in consistency and accuracy.

The UIC MOD 2 incorporates many of ADM’s latest features to include:

UIC Billet Upper Receiver

The UIC MOD 2 has an upper receiver made from machined 7000-Series T6 aluminum, which includes a hard coat anodized finish (per Mil-A-8625F, Type III, Class 2) with M4 feed ramps that provides for consistent chambering and smooth transition from magazine to barrel. The UIC MOD 2 is designed in the unique ADM fashion, though consistent to the Colt format.

ADM Premium Bolt Carrier Group (PBCG)

ADM invested some of its greatest effort, and attention in detail to developing the PBCG in its UIC MOD 2 rifle. With a bolt made from 9310 steel, and the carrier itself made of 8620 steel, the EBCG includes a Carrier Key, Cam Pin, and Extractor in 4340 steel. The carrier includes a black Nitride finish and is high pressure tested, mag particle inspected for any flaws, cracks, or failures in the materials. Even the hex-head screws are Grade 8 hardened for extended durability despite the abuse.

Raptor Ambidextrous Charging Handle

As part of the UIC MOD 2 design, ADM includes the Raptor AmbidextrousCharging Handle from Radian Arms. The charging handle itself is made from aircraft-grade 7075-T6 aluminum, which is a material widely known for its strength. Dual latches on either side allow for ambidextrous operation of the charging handle whereby the palm can be used in a “bladed” fashion, or in the more typical finger/thumb use. The Raptor is anodized to the same MILSPEC standards as the upper receiver.

Criterion Hybrid Barrel

At the heart of select versions to the UIC MOD 2 is a Criterion Hybrid profile barrel. In the instance of an 18″ barrel, the Hybrid is made from Stainless Steel 416R (with a Nitride Finish) whereas the 10.5, 12.5, 14.5, 16″ barrels are made from 4150 Chrome Moly Vanadium (CMV) steel. In contrast, other select barrels in the MOD 2 line (11.5” or 13.9”) are also made by Criterion, but utilize the CORE profile barrel also made from 4150 CMV. The Hybrid barrels emphasize the same accuracy and balanced weight with a continual profile the full length of the barrel. The Hybrid barrel utilizes the same 1 in 8 twist as the CORE, and is chambered in the more modern .223 Wylde that gives the largest level of stabilization and utilization between 5.56 NATO and .223 caliber ammunition. The Hybrid barrel’s bore is hand lapped with 1/2×28 TPI threading (to accommodate a variety of aftermarket devices), and overall finalized with a nitride finish to prevent any corrosion. The barrel itself has a gas port of 0.0925” for use with or without suppressors, and allots for a gas block with a .750” journal and dimpled for a set screw.

Surefire Warcomp Flash Hider

At the front of the MOD 2 ADM has elected to use a Surefire Warcomp flash hider. The three-prong design of the Warcomp comes from a single bar of stainless steel that eliminates 98% of the overall flash from a rifle, and the porting all but eliminates muzzle rise caused by recoil. These features also provide multiple surfaces for suppressor alignment, although the Warcomp can also be timed for either neutral, left, or right-handed shooters. To finish out the flash hider, the Warcomp is DLC-coated for improved durability and longevity.


At the forend of the UIC MOD 2, ADM has designed proprietary MLOK handguard that is made from 6061 T6 aluminum, with clamping screws, and anti-walk screw, and an anti-rotation pin. This ensures proper alignment, and no inadvertent “walking” of the handguard over time due to recoil. ADM offers the handguard in either black hard coat anodization, or in an optional cerakote finish (wait times apply).

UIC MOD 2 Specifications:

  • Variable lengths:
    • 10.5″, 11.5″, 12.5″ (for use on AR pistols)
    • 13.9″, 14.5″, 16″, and 18” (for use on rifles)
  • Uppers at 13.9″ and 14.5″ are pinned/welded
  • Materials Used in 18” UIC MOD 2 complete upper receiver:

The overall UIC MOD 2 Upper Receiver with 18” barrel is available in anodized Black (featured), or can be cerakote to OD Green, Grey, Midnight Bronze, or FDE (wait times apply).

***Editor’s Note: For the purposes of this review, the UIC MOD 2 18” upper receiver was paired with a demo Aero lower using a LaRue MBT. Additionally, other accessories were added as testing became more complex. These elements were not factored as part of the upper receiver’s evaluation and merely used to assist in testing).

Product Evaluation Scores:

  • CostAverage (3/5): With its MSRP of $1,560 (regardless of barrel length), the UIC MOD 2 represents an effort by ADM to bring together many industry-leading materials and provide a product that delivers consistent accuracy and function. The volume of overall steel and aluminum used is comparable to other leading upper receivers, illustrating ADM’s efforts to make its UIC line a popular option to the consumer. In contrast, comparable market alternatives using similar materials, twist rate, and design would be an SR-15 18” Complete Upper ($2,093) from Knight Armament Company, a 18” DDm4v7 Pro ($1,496) from Daniel Defense, or the AR-15 SPR Gen 3 18” Upper Receiver ($1,600) from Noveske. Other market alternatives for 18” upper receives are available, such as the M4E1 Complete Upper Receiver ($554.99) by Aero Precision, but often these do not include features like a bolt carrier group and charging handle (which would need to be purchased separately). And while the “debate” of value to the consumer’s preferred brands is a hotly contested topic—for the cost and quality/volume of materials used, and amid the market of listed competitors, the UIC MOD 2 is of an appropriate (or average) cost. It should be noted, that some alternative companies (such as KAC) producing high-cost rifles also strongly limit the number of products released to the public, thus that product rarity alone can also be a driving external factor to cost. ADM does not follow that practice, and releases products as soon as it can be manufactured and inspected at its factory in Wisconsin. 
  • Comfort Good (4/5): From a comfort aspect, the 18” UIC upper had two significant elements that contributed to a greater level of end-user comfort that mitigated impulse and recoil—the longer gas system/barrel, and utilization of the Surefire Warcomp. The gas system itself starts with a 0.0925” barrel port that was sized for use with or without suppressors (use of which was not evaluated), but also did not throw any excessive volume of gas back into the face or otherwise within the immediate field of view during the firing process. Additionally, the longer rifle-length gas system also allowed for ejected brass to consistently be thrown at the appropriate 3-4 o’clock position. This allowed the UIC to continually run, and at no point during evaluation did the 18” upper receiver BCG fail to eject or feed. Likewise, the Warcomp was an improvement over the standard A2 birdcage that is common to market alternatives, and in video of the firing sequence it demonstrated the blast mitigation through distributing gas and pressure outward/upward to prevent associated muzzle rise. This further aided the end-user to stay on target through consecutive rounds and maintain sight picture. With regards to rounds fired, one common negative issue with MLOK style rails (such as experienced in the shorter 13.9” UIC upper) is the level of thermal emission as it relates to the position of the support hand and the gas block/barrel. This problem was not observed/felt in the longer 18” version as there was a longer barrel and gas system by which to distribute the heat over greater material. Lastly, while the Criterion Hybrid barrel (in select UIC models) does not have the taper of the CORE (as found in the 11.5” and 13.9” UIC barrels), that continual profile was intended to maintain the accuracy of the overall barrel as it heats up over sequential shots with minimal effect to weight forward of the rifle.
  • Durability – Good (4/5): The durability of the 18” UIC MOD 2 distilled down to the quality of materials selected for the upper receiver; specifically the use of appropriate aluminum in various components where heart resistance was needed, and steel used elsewhere for rigidity and longevity. There is a lot of pressure, heat, and force involved in the science of a rifle’s firing sequence and all of it was demonstrated during evaluation. In our video review, kinetic torsion (a.k.a. barrel whip) of the Hybrid barrel, similar to that demonstrated by Larry Vickers in a BCM 4k UHD slow-motion video, was minimally observed and the barrel would immediately return to its initial state before the next round was fired. Even under rapid fire that same torsion only minimally effected the barrel’s accuracy (excluding factors related to the shooter themselves) due to mainly to the Hybrid barrel’s continual profile and use of 416R steel. Other manufacturers often opt for lesser quality steel or use a nitride on their barrels over chrome – a decision that is a cost-saving choice but has its tradeoffs. ADM states “All out barrels are nitride finished and we have found this to be a superior barrel/bore treatment over chrome-lined in both durability, longevity, and provides a slight velocity gain”. But the choice of materials in the 18” UIC MOD 2 shows ADM put the durability of the upper receiver’s components in mind from the beginning. Some minimal surface marring (due to dynamic drills and contact with surfaces), and typical friction point wear (specifically with the BCG and charging handle) were noted over the course of the review, but these all fell within expected results given usage. The BCG gas key was notably mechanically staked for an adequate friction lock—though did not peen the screwheads significantly and was inconsistent between both screws. Over the course of review no negative effects (cracking, warping, sub-surface marring) to durability of the upper receiver were noted, and given the performance characteristics of the 9310 steel, 8620 steel, and Stainless Steel 416R the odds are the upper receiver itself will continue to withstand substantial usage over the long term.
  • Functionality Excellent (5/5): From a functional aspect, the 18” UIC MOD 2 upper was evaluated over the course of roughly two months, using approximately 800 rounds (predominantly personal reloads using Hodgon CFE 223 powder and 55gr or 75gr match grade projectiles), and approximately 200 rounds of factory ammunition in various projectile weights (between 55gr and 62gr) and of different composition. While initially iron sights were used to establish a basic zero and break-in period, a 5×25 Vortex optic was eventually rotated in and the upper receiver’s performance was monitored. For best available accuracy purposes, a bench-supported and mechanical-supported (bipod) position was used, though more dynamic drills were utilized for target transition/rapid fire performance. With factory ammunition, the 18” UIC MOD 2 upper receiver achieved and maintained a tighter MOA than the 13.9” UIC MOD 2 upper receiver (although both reached the 1” MOA as advertised). A sub-1” MOA would be very possible if the end-user benched the overall rifle into a more fixed device like a vice or other platform. The 18” barrel’s performance was attributed to the greater barrel length, with more rifling/landing surface in contact with the projectile as it traversed through its 1in 8 twist ratio. The groupings were noted tighter with projectiles in the high 60s and mid 70s grain weight as opposed those with the lighter 55 grain. This tighter performance also allowed easier optic adjustment at 300yds, and accuracy results were consistent (excluding shooter error :-/). At no point during evaluation did the upper receiver fail to cycle or eject, even with reloaded ammo (sized to SAAMI specs), giving it an excellent performance. Other more minute aspects of function, such as the performance of the Warcomp and gas system were addressed above in the Comfort section.
  • Weight Good (4/5): As a complete upper receiver, the 18” UIC MOD 2 weighed in at 4.91 pounds (or 78.7 ounces). Given the combination (and volume) of steel and aluminum selected for its components, this put the 18” MOD 2 at a good overall weight for an upper receiver that was not significantly fatiguing to use, nor fatiguing on the shoulders/upper torso to carry over distances. In contrast, the SR-15 18” Complete Upper (4.3 pounds) from Knight Armament Company, an 18” DDm4v7 Pro (5.25 pounds) from Daniel Defense, or the AR-15 SPR Gen 3 18” Upper Receiver (7.5 pounds) from Noveske all demonstrate that in comparison the 18” UIC MOD 2 upper is among the lighter of its competitors due in large part to the choice and design of materials used. But end-users should bear in mind that while ounces in rifle mass can be incidental, the greater the mass, the more recoil absorption there will be. ADM has made efforts to balance these effects while keeping the overall weight of the upper receiver to a minimum.

Overall Rating – Good (20/25)

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I am reviewing this product as a courtesy to the manufacturer and via High Ground Media, LLC, so that I can evaluate it and provide my honest feedback. I am not bound by any written, verbal, or implied contract to give positive reviews. All views are my own, and based off my personal experience with the product.

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