Gun Review: Adams Arms C.O.R. Ultra Lite Rifle

By Nick Leghorn on November 27, 2014

Over the last couple years, there has been no bigger influence on the firearms market than the emerging sport of 3-gun shooting. As the number of participants has skyrocketed, so too has the number of rifle manufacturers producing firearms to feed that voracious market. Everyone and their brother has a rifle optimized for 3-gun shooting these days, and figuring out which rifle manufacturers have got their heads screwed on straight and actually understand the challenges of the sport can be a challenge. Adams Arms recently introduced a line of rifles specifically designed for 3-gun shooting, and they sent one to me to test out.

The name for their line of high-speed low-drag rifles is “Competition Optic Ready” or “COR.” The way they market these rifles is that the guns are designed and built by pro 3-gun shooters, and therefore the only thing you need to do after it shows up on your FFL’s doorstep is to add the optic of your choice. When it comes to optics, some people like red dots. Others like massive 3-9x power scopes. It’s all a matter of preference, but what generally isn’t contested is the overall design of a great 3-gun rifle. The details are up for debate, but if the overall package is solid then you should be good to go. In general, it looks like the COR line has lived up to those specs.

The tagline for this specific rifle is “Ultra Lite,” indicating that it was designed with an eye towards shedding as many ounces as possible. One of the first things to be sacrificed in the name of shedding weight is the buttstock, and Adams Arms has gone with a Magpul MOE fixed rifle stock instead of a more traditional ACS-L or even PRS stock. It’s definitely lightweight, and for me personally I find it to be the exact right length to fit my body, but it’s not perfect for everyone. You trade off weight savings for comfort, but in general this stock should fit most people just fine.

Moving slightly forward, we come to the fire controls. Adams Arms has been using the Hiperfire triggers for ages now, and personally I’m a fan. They are easy to tune and offer a crisp and clean break, which is a huge improvement over the standard mil-spec garbage that most companies half-heartedly shove in their firearms on their way out the door. The trigger is one of the most important bits on a rifle, and I’m glad to see that the Adams Arms guys haven’t skimped.

The other fire controls are acceptably nice as well. The safety selector is right-hand only, but lefties can easily swap that out if need be. The grip is a Magpul MOE grip, which isn’t as nifty as a MIAD but it’s perfectly fine. There’s a plastic trigger guard (again, weight savings taking a priority here) underneath, but only a standard charging handle up top. The rifle also comes in a variety of paint jobs, for those wanting to stand out visually. Or you can get it in plain black and be boring.

The real nifty stuff, though, is out front.

The rifle sports a 16.5 inch barrel, and a Samson free float handguard surrounding it. Samson makes some good stuff, but they are still using semi-proprietary screw-in rail segments when the rest of the industry seems to be quickly moving to either keymod or M-LOK based rail mounting systems. It somewhat limits your choices when it comes to sticking things on your gun, but for 3-gun you’re going to want to be running as slick as possible anyway.

The muzzle brake is a competition legal VDI Jet comp, which does a fine job of mitigating the recoil of the 5.56 NATO based platform. The gun is rather lightweight, so while the “punishing recoil” of a 5.56 cartridge would normally not be an issue it becomes slightly more annoying in a featherweight gun. With the brake installed the recoil is still a touch heavier than in my usual competition rifle, but it isn’t terrible.

The real difference between any old rifle and an Adams Arms rifle is the gas system. Adams Arms uses a short stroke piston system instead of a direct impingement / gas expansion system like the normal AR-15 rifles, which seems to keep the gun cleaner and operating longer than with conventional systems. Of all the short stroke piston systems on the market I like the Adams Arms adaptation best, simply because it is a dead simple design executed very well that is incredibly easy to disassemble and clean.

For their COR rifle, Adams Arms has designed a low-mass bolt carrier. Havng a lighter bolt carrier does slightly reduce he overall weight of the gun, but the real benefit is that a light bolt carrier requires less force to move around than a standard BCG, which means reduced felt recoil due to the operating parts moving around. It’s a good theory, but in practice it still seems to have some issues. The first time they sent me the COR rifle the gun refused to cycle — it would eject the spent cartridge but fail to pick up the next round off the magazine. It’s a classic symptom of an under-gassed operating system, but even running the adjustable gas block in the widest setting available the gun wouldn’t cycle. Adams Arms’ guns are all under a lifetime warranty, so I sent it back and the one they returned worked perfectly. It would be nice if it had worked the first time, but they made it right so I’m not that concerned.

What does concern me, though, is the barrel.

This is a “lightweight” rifle build, which means they have taken every ounce out of the gun that could possibly be removed. From a low mass carrier to a lightweight buttstock, there’s nothing left on the rifle that is extraneous. So when it comes to the barrel, the same thing has been done — to disastrous results.

With barrels, despite what some people might believe, the length of the barrel doesn’t have any appreciable impact on accuracy. Long or short, it doesn’t matter that much. What does matter, however, is the quality of the barrel. A stiff short barrel will do wonders for accuracy, but a skinny long barrel is damn near useless past 100 yards. With the Adams Arms COR Ultra Lite rifle the barrel has been profiled down to a pencil thin strip of steel containing the expanding gasses, and as a result the barrel has a tendency to whip around a bit when firing. In fact, the barrel is so thin that I can make it deflect about a half an inch at the muzzle using nothing more than my thumb and forefinger. That barrel movement translates into some painfully dreadful results downrange.

This five round group was shot at 100 yards off a rest, and is the best group I had all day out of the gun. The extreme spread of the group is right around 2 MoA, which is OK for a off-the-shelf bargain bin rifle but terrible for a “competition” gun. I take that back — it’s terrible, depending on what you need it to do.

It seems like this gun was designed for the 3-Gun Nation series courses of fire, where the furthest targets are 6 inch steel plates at 50 yards and the whole point is to go really really fast. In that situation, this gun wouldn’t be too bad. It cycles quickly, recoil isn’t bad, and the light weight means you have less mass to lug around with you through corners and around tight bends. It should do just fine in that environment.

The problems start when you move out into the “real” world of 3-gun. 3GN matches are designed to look good on camera, but th average 3-gun match is much different. I don’t think I’ve ever been to a match that didn’t have at least one difficult 100 yard shot, and testing the shooter’s ability to transition from quick close-range targets to small long range targets in a single stage is something that match designers love to do. The best plan for those kinds of matches is to bring an accurate rifle, as the more accurate your rifle is the less accurate you need to be. When seconds count and you need to take a less than ideal shot from a compromised shooting position, having a smaller “cone of uncertainty” with your rifle means you can get good hits with an okay sight picture instead of needing to be dead-on every single time. It saves time, and in matches where the targets can be 500+ yards away it can make all the difference.

There’s nothing necessarily “bad” about the AA COR Ultra Lite rifle, the designers have simply made some compromises in order to maximize one statistic over another. In this case they prized a lightweight gun over a super accurate gun, and the result is what you see here. This is a rifle that would be absolutely perfect for the 3GN style matches or most east coast based 3-gun clubs, but for anything in Texas or Arizona (where the long range stuff is king) I wouldn’t even want to try running it with this gun. The only real problem is the barrel — if the guys at Adams Arms had used a slightly thicker profile (and therefore increased the weight a touch) it would be a much better all-around gun, but then it wouldn’t have been as light.

No gun will be all things to all people — all guns make some trade-offs. In this case, the trade-off wasn’t advantageous for me in Texas. But if you’re looking for a featherweight AR-15 rifle with a great piston system that’s ready to go for short range 3-gun matches, this is a great choice.

Specifications: Adams Arms C.O.R. Ultra Lite Rifle

Caliber: 5.56 NATO
Action: Semi-auto
Barrel: 16.5″
Magazine: Standard AR-15
MSRP: $1,799.61

Ratings (out of five stars):

Accuracy: * *
For the price, definitely sub-par. But then again, that was by design.

Ergonomics: * * * *
Lightweight and maneuverable, this thing is definitely very cool. It loses a point for the fixed rifle stock, though.

Ease of Use: * * * * *
Light recoiling, easy to disassemble gas system, and dead nuts simple field stripping make this a breeze to use.

Reliability: * * * *
I have to knock off a point because the gun didn’t work out of the box, but a trip back to Adams Arms and they fixed it. Zero malfunctions since the trip to the shop.

Customization: * * * *
I’d really love to see a slightly thinner handguard with some keymod or M-LOK attachment points. The Samson rail is cool, but keymod is cooler.

Overall Rating: * * *
This one was really hard for me to decide. I like almost everything about this gun — the stock, handguard, and trigger are all quality stuff, the piston system is really nifty, and even the bolt carrier is decidedly cool. But I think they went a step too far with the barrel profile, and traded off too much accuracy in the pursuit of weight savings. For a 3GN shooter this might be perfect, but for the average Joe dropping over a grand and a half on a competition rifle they need to use it in more than one hyper-specialized subset of 3-gun. As an ultra-light rifle this is a great choice, but it isn’t versatile enough to use for any other purpose. I’d be less disappointed if there were a version with a slightly heavier (and more accurate) barrel available as well, but alas this is all Adams Arms has at the moment for the C.O.R. line.