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Adams Arms (AA) Evo Ultralite Ultra-Light/Super-Lightweight Gas Piston/Op-Rod AR Carbine Upper Receiver Assemblies (Mid-Length and Carbine-Length) for 3-Gun Competition and Combat: Super-Accurate and Super-Fast!

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By Jeff Gurwitch

July 25, 2011

When I first saw that Adams Arms (AA) was going to offer a super-lightweight upper with a “pencil thin” barrel, I was very skeptical. I could not help but think back to my time in basic training many years ago, where I was issued a M16A1. Thin profile barrels just seemed flimsy and out of date to me. After years of running the heaver M16A2 profile and the M4A1 heavy-profile barrels, I’ve become very use to and comfortable with running a heavier barrel. If you asked me 3 months ago what I thought about thin barrels, I would have said they are a step back. Now, three months into testing and running two different Adams Arms Evo Ultralite gas piston/op-rod (operating rod) complete upper receiver assemblies, I can’t see myself running anything but one for my primary 3-Gun competition rifle!

The Line Up

Before I get into explaining my reasons and preference for now running an Adams Arms lightweight upper exclusively for use in 3-Gun competition, I will first start by going over the specs of my two test guns:

I received two uppers from Jim Granger at Adams Arms. The first was a production model Evo Ultralite carbine length piston upper. The upper comes with a 16-inch (16″) lightweight barrel and lo-pro (low-profile) gas block, and is fitted with the new Samson Evolution forearm. The second upper is currently not being offered commercially, but Jim sent it to me as a platform just to test the accuracy of the barrel. It’s an Adams Arms competition monolithic upper. Instead of the normal 16-inch stainless steel fluted barrel, this one came equipped with a mid-length piston system and a 16″ lightweight barrel.

Both barrels are fitted with an Adams Arms compensator, utilize a 1/7″ twist rate, and are melonited as opposed to chrome lined. The only difference between them is the gas piston/op-rod system length. One is carbine-length, while the other is mid-length. The production model carbine upper alone weights 4.5 lbs. When I mounted it on a lower with a VLTOR IMOD (Improved Modstock) buttstock, kitted it out with a C-More Systems red dot sight and Magpul RVG (Rail Vertical Grip), the entire gun weighed in around 6.5 lbs dry/empty without magazine . The monolithic upper mounted to the same lower with a Vortex Viper PST 1-4×24 Riflescope tactical scope and Magpul AFG (Angled Fore Grip) came in just under 8 lbs empty.


Probably one of the biggest concerns a lot of people have–not just with thin barrels, but with piston systems in general–is accuracy. With all the previous Adams Arms piston system uppers I’ve used, I’ve found them to be just as accurate as any other major brand AR-15 out there on the market. One rumor that still seems to persist out there on the internet is that the motion of the piston going back and forth during firing can affect the barrel. The result is vertical “stringing” of the shots from the piston moving the barrel up and down. However, I have never seen or experienced this with Adams Arms systems or any other piston system I’ve tried. That being said, though, I figured that with the barrels being so thin on these Evo Ultralites, if it were going to happen, this would be the time. So, my first goal was to shoot these two uppers and see what I could ring out of them in terms of accuracy.

First up, the carbine length piston upper; using a C-More red dot sight with 2-MOA dot at 25 meters, I zeroed it with a hold-off for a 200m (200-meter) point of impact. During zeroing, right out of the gate, I had no issues shooting 3-round dime-sized groups with XM193 55gr ball ammo (used throughout for all the shooting with these uppers). Now that it shot good groups under slow fire, I wanted to see if this lightweight barrel would be able to hold a group once the barrel heated up.

For this, I conducted two different tests. First, a buddy of mine (a very good shooter and CQB instructor) jumped down and with three mags commenced shooting a 90 round group, again at 25 meters. The resulting group did go from dime size to just under two inches (2″). No point-of-impact shift. The group just spread out some. I’m sure some of the spread can be attributed to the shooter trying to shoot 90 rounds as accurately as he can in one sitting. After that, we took about a 5-minute break, shot a new group, and it was back to dime size. I’m pretty pleased with the results. Lightweight barrels have been known to drop accuracy when they get hot enough. My worry was the point of impact would change once the gun got a little hot, but, this was not the case. The group did open up some, though. Whether it was from heating up or just the shooter, it’s hard to say. But, so far, I thought that was pretty good. The next test: at 25 meters I fired 3 mags on semi (semi-auto) as fast as I could in 5-round strings, then immediately jumped down and shot a 3-round group, which was just about dime sized.

Now, to judge accuracy of a system, you obviously have to take into account the ammo and optics used. For my standard, I base a lot off the optics I use. My expectations for a rifle with a red dot versus using a powered scope are different and based off what I know I can do with each. Having said that, here’s what I was able to do shooting prone supported with the carbine-length lightweight upper using a C-more red dot: At 100 meters using XM193 55-grain ammo, I could consistently put 5-round groups onto a 3×5 card with no problem. This is about the max the ammo can perform, anyways.

Switching to the monolithic upper with the Vortex scope, I could get 1-inch (1″) groups at 100 meters. Going back to 250 meters, I was able to post approximately 5-6 inch groups with 5-round strings. Now, I have not used any match grade ammo with these lightweight thin barrels, but based on what I was able to achieve with standard ammo, I’m pretty confident I can achieve even tighter groups at the same ranges using more accurate ammunition.

Performance Under Pressure

So, with zeroing and grouping out of the way, it was time to hit the matches. Over a period of 3 months, I used both uppers in numerous local 3-Gun matches. I’ve gotta’ say I’m impressed. Not only did these uppers run flawlessly, they performed outstandingly at distance. Even just using a red dot sight, I had no problems getting first-round hits on 6, 8, and 12-inch plates and LaRues (LaRue steel targets) out to 300 meters. One thing I do want to mention is velocity. I have not yet had the chance to chronograph these uppers, but based on how they’ve been performing, I bet they must be pushing 3,000 fps. Normally, with a 14.5 chromed line barrel (which is what I normally run) I get about 4 inches of drop at 300 meters using a 200-meter zero . So, for anything past 200, I just hold 12 o’clock high. Using these uppers with the melonited 16-inch barrels, I’m holding center mass out to 300m and getting hits. For a competitive shooter like me, that’s outstanding. The more you can just hold center without having to play around with holds, the faster times you can achieve on the long range stages, usually. During matches, that’s exactly how these guns performed.

So far, I’ve only been talking about the accuracy of these uppers. I would be doing an injustice if I did not also mention how smooth these uppers shoot. If you ever ask me what type of system to buy–mid-length or carbine length–regardless if it was DI or piston I would say get yourself a mid-length system, since they generally have less felt recoil. The Adams Arms compensator works so well with the Evo Ultralites that I really could not tell the difference in recoil between the carbine-length and mid-length (monolithic) piston uppers. Both uppers had almost zero recoil–perfect for 3-Gun competition!

The Wrap Up

We’re going on 4 months now, and I’ve been using both these uppers on the flat range and in 3-Gun competition. They’ve both proven accurate and fast-handling. As I said in the beginning of this article, they’ve replaced my other uppers as my primary choice for a competition upper. So, If you’re in the market to build a dedicated 3-Gun competition rifle, and you’re looking for a fast, accurate, reliable and super-lightweight set up, then I don’t think you need to look any farther than an Adams Arms Evo Ultralite!

Editor’s Note: Notice the Arredondo AR Magwell magwell extension and Lancer L5 AWM (Advanced Warfighter Magazine) translucent polymer 30-round mags in the accompanying photos.

Adams Arms Evo Ultralite Piston AR Upper Receiver Features and Specs (from Adams Arms):

“- Melonite coated barrel: Melonite coating reduces internal barrel friction which extends the barrel life. Melonite coating also improves accuracy due to tighter coating tolerances and improves muzzle velocity by over 100 FPS. With no chrome lining to flake or peel over time, these melonited barrels will outlast hard chrome lined barrels two to one!
– Low profile lightened gas piston system
– Lightweight design: Weighing in at only 4.2lbs it is the lightest gas piston accessorized upper on the market. Period!
– Adams Arms Competition Muzzle Brake: This industry leading front compensator allows the shooter to stay on target, eliminates muzzle rise and significantly reduces recoil allowing for faster follow up shots.
– First and only 62.5 gas piston system and upper
– Modular tubular design: The only tubular modular upper on the market (other than Adams Arms very own competition upper.)
– Samson Evolution Ultra Light rail: The Samson Evolution Series rail is the next step forward in free floating hand guards. Light weight and durable these offer the perfect upgrade for 3 gun shooters, LE/Military or weekend enthusiasts alike. The 1.8” facetted O.D .offers a comfortable shooting platform while not being to large for most shooters. Accessory rails can be added or removed easily to adapt the hand guard to your needs (units can also be mounted at 45 degree offsets).”

Photo(s) Credit: Jeff Gurwitch

About the Author (Jeff Gurwitch):

– Has been a competitive shooter for the last 10 years: USPSA, IDPA, and 3-Gun.
– U.S. Army 3rd Special Forces Group, Ft. Bragg, NC.
– Spent 3 years as an instructor at the John F. Kennedy Special Warfare Center and School
– Spent 8 years with U.S. Army 5th Special Forces Group, Ft. Campbell KY and did 3 tours in Iraq.
– Graduated the U.S. Army Special Forces Qualification course in 1998 as a Weapons Sergeant.
– Spent 7 years in the mechanized infantry and Airborne.
– Served in First Gulf War (Operation Desert Storm) in Iraq with the 1st Armored Division.
– Joined the U.S. Army in June of 1990 as an infantryman.

Company Contact Info:

Adams Arms
612 Florida Ave.
Palm Harbor, FL 34683
Toll Free: 877-461-2572
Local: 727-853-0550
Fax: 727-853-0551
Email Sales:
Email Jim Granger:

Samson Manufacturing Corp. (SMC)
110 Christian Lane
Whately, MA 01373
Toll Free: 888-665-4370
Office Phone: 413-665-1162
Fax: 413-665-1163

© Copyright 2011 and Jeff Gurwitch. All rights reserved. This content/material may not be republished, broadcast, rewritten or redistributed without first receiving permission and providing proper credit and appropriate links.

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About David Crane

David Crane started publishing online in 2001. Since that time, governments, military organizations, Special Operators (i.e. professional trigger pullers), agencies, and civilian tactical shooters the world over have come to depend on Defense Review as the authoritative source of news and information on "the latest and greatest" in the field of military defense and tactical technology and hardware, including tactical firearms, ammunition, equipment, gear, and training.

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