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The Modern Sporting Rifle seems to have a polarizing effect on shooters and non-shooters alike, at least in my experience.
To an old-school rifle shooter, an AR-style rifle is anathema to his or her way of thinkingâ¦rifles are supposed to be wood and metal with no plastic.
I am a fan of the MSR, or the âBlack Rifleâ as some call it.
So, it was with a bit of enthusiasm that I accepted the offered test gun from Rock River Arms, their Rock River Arms LAR-15 BTB 5.56Ã45 rifle, in tan and black.

As you can see, it’s a rather handsome specimen with its two-tone finish and furniture. It was a decent shooter as well.
- Collapsible buttstock
- Reliable
- Sights are easy to adjust
- Front post is black and hard to pick up
- Drop-in rail has limited customization options
Before we get on with things, let’s take a brief look at the history of the AR platform, both military and civilian.
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Stoner’s Brainchild

It started in 1956. Eugene Stoner had designed the AR-10 in 7.62 NATO. The cartridge was adopted two years earlier. At that time, the United States Army was thinking of replacing the M1 Garand. They even considered rechambering the Garand. They were open to suggestions, and this was as good a time as any to introduce a new rifle. So, Stoner submitted his rifle and got rejected. However, it few foreign militaries started taking note.
As we know now, the army settled on Springfield’s M14 in the end, but it was big and heavy. Some of the powers-that-be wondered if they needed a full-size battle rifle that’s good at 600 yards. Modern confrontations were occurring at closer ranges, usually less than 300 yards. It was around this time that Russia introduced a midrange .30-caliber round, the 7.62×39. They started to deploy it in earnest during the 1950s in the AK-47. This, of course, wasn’t a full-power rifle round, a fact that’s duly noted by the US defense department.

At that time, Remington introduced the .223, which became the 5.56Ã45 in military rifles’ chambers. For a concise description of the difference between .223 and 5.56, go check the history of the 5.56Ã45 NATO.
Enter Colt
In 1959, ArmaLite was having financial difficulties. It couldn’t meet manufacturing needs, so it sold the AR-15 to Colt. Colt undertook production of the AR-15, which morphed into the selective-fire M16.

In the early 1960s, the U.S. sent observers, trainers, and Special Forces troops to Vietnam. This started as an effort to train indigenous forces against the communist North Vietnamese Army and the Viet Cong. They ranged from North Vietnam, employing standard military operations and guerilla tactics in forays across the border with South Vietnam.
As we know now, this grew into what became the Vietnam War. Everyone knows the story, such as how relatively few troops were committed at the start. By the time the U.S. left Vietnam in March 1973, it had placed more than 550,000 military personnel in the country. This isn’t a comment about that war as I have only admiration and respect for all who served. I was only showing why we needed a whole lot of rifles and ammunition. Unlike the .30, we didn’t have tons of 5.56 ammo lying around. So, the ammo companies geared up to supply them.
An interesting side note â U.S. Defense Secretary Robert McNamara decided the fate of the M14. He concluded that the M14 was:
- Too expensive to produce.
- Too big and heavy.
- Fired a needlessly overpowered round.
He asked that the AR be put into production, albeit with selective-fire capabilities. We went from a full-power .30 caliber battle round to a .22 caliber midrange round. Some folks liked it; others, not so much.
You know the rest:
- Winchester, which was brought on board to help produce ammo, went from a stick powder to a ball powder
- How that caused increased pressure and fouling
- Telling troops that their M16s didn’t need cleaning caused battlefield issues
Moreover, this put many soldiers and Marines in great danger. Worse, some rifles quit working in the heat of battle due to fouling and jungle crud buildup. We then figured out that these rifles did indeed need to be cleaned, and that helped to lessen the problem. Other positive changes included the forward assist on newer models. Winchester also went back to the original stick powder. If you served and have experience with this situation, please leave a comment below â I’d like to hear your take on it. For an interesting read, check out this article about the history of the AR-15/M16 rifle.
Now that we’ve seen where the AR-15/M16 came from, what about the company that made the Rock River Arms LAR-15? Let’s check it out.
A Bit of History on the LAR-15
Brothers Mark and Chuck Larson worked for Springfield Armory. Mark was the head armorer. They formed a partnership, leaving Springfield Armory. in 1991 to work with Les Baer in the production of his custom 1911 pistols. In 1993, they left Les Baer Custom to work with Eagle Arms in Coal Valley, Illinois, producing AR-15 rifles. Tolerance Plus was founded as a result of their efforts (later Rock River Arms). They began making 1911 pistols. In 1997, they quit Eagle Arms and began creating AR-15-style weapons. Mark died in April of 2013.
A Big Order From the DEA
The U.S. Drug Enforcement Administration was looking for a new AR-style rifle in 2003. It tested 11 different brands, with Rock River Arms coming out on top in abuse tests. The contract called for at least 5,000 rifles to be purchased during the next five years. As a result of the DEA’s order, the FBI and the U.S. Marshals initiated piggyback contracts with Rock River Arms. These two brothers did very well for themselves.
The reputation of Rock River Arms was built on AR-15-style rifles. To this day, Rock River Arms produces seven different 1911-model pistols and lots of related parts. It started out with pistols and has stuck with them. The company is based in Colona, Illinois.
Here to Stay
Whether you’re an AR fan, they are here and will most likely stay for a good while. There are a seemingly unlimited number of ARs out there and at least as many aftermarket parts for your rifle. If the 5.56 or .223 isn’t your thing, guns are available in several other calibers. We are seeing an increasing number of ARs in the hunting fields, chambered for mid-level hunting rounds such as the .300 Blackout and the new .350 Legend.
In my opinion, this is a good thing. I am not the most rabid AR fan out there, but I do own one. I could easily buy an upper in one of those calibers and take it to my deer blind. The AR MSR is, as stated, a polarizing weapon. If more folks could see that it has a purpose other than as an “instrument of destruction,” we might all be better off. Adding in three-gun and other types of competitions, we start to see the AR in a more generalized light. I think it’s a good thing.
Versatility and Modularity
Another plus of the AR-style carbine is the availability of aftermarket parts. I may have joked about it, but part of the draw is the ability to change just about anything on your AR. From triggers, folding sights, and lights to a new upper, you can customize the AR to your heart’s content. I’ve heard it referred to as the “Barbie of rifles.” I am thinking about getting an upper in .350 Legend.
The new Winchester round seems like a useful cartridge around my neck of the woods. It’s easy â just buy the new .350 upper from Bear Creek Arsenal or Rock River Arms and stick it on. As you can see in some of the photos, the handguard rail is on the top and bottom. Then, there’s just enough of a small rail on each side at the forward end of the guard. Put a laser or light there â I like the possibilities. These are only a few of the possibilities available when upgrading an AR rifle.
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The Rock River Arms LAR-15 BTB Rifle
Let’s look at the specific gun I was sent to review, a Rock River Arms LAR-15 BTB rifle. In case you’re wondering, BTB stands for “Beyond the Basic.”

Caliber | 5.56 NATO/.223 |
Lower Receiver | Forged RRA LAR-15 |
Upper Receiver | Forged A4 |
Barrel | 16-inch chrome-moly HBAR, 1:9 twist |
Muzzle Device | A2 flash hider, 1/2-28 thread |
Gas Block | Low Profile |
Trigger | Single-stage |
Pistol Grip | RRA NSP Overmolded, Tan |
Buttstock | RRA NSP-2 CAR Stock, Tan, multiposition |
Handguard | RRA NSP Drop-In Rail, CAR-length, Tan |
Sights | RRA NSP Flip Front & Rear, Tan |
Weight | 7.0 pounds |
Length | 33.25 inches |
Accuracy | 1 minute of angle (MOA) at 100 yards |
Includes | Two RRA 30-round tan magazines, hard case, owner's manual, warranty information |
MSRP | Limited Time: $825 (real-world pricing starts around $750) |
Warranty | Limited Lifetime, original purchaser, with the usual limitations |
One thing not mentioned is that the gun functions via direct gas impingement, not a piston system. I guess that would be obvious when it mentions a gas block, but I’m not one for the obvious at times.
Photo Gallery
Here are some photos of the test gun I had. A quick observation â the tan goes with the black very well. At least I think so.

The BTB in tan. It also comes in black.



The collapsible buttstock can be adjusted in six positions.

Here’s a close-up photo of the front sight. Notice how easy it’s to adjust elevation.




Here are shots of the rear sight. Again, there’s that obvious ease of adjustment.

Close-up of the handguard. Note the small rail on the sides.


Front and rear sights folded down.




Two 30-round magazines are included.

Standard A2 flash hider. You can replace this with something else if desired.

Magazines
The tan furniture blended nicely with the matte black of the body. I have seen many ARs finished in a similar manner, but the Rock River Arms LAR-15 was especially well done. Even the pistol grip was blended nicely, exhibiting both black and tan colors. Both mags were tan, as you can see from my pics. Speaking of mags, they didn’t send 10-round magazines. Instead, they went for the “full meal deal” on the 30-round extended mag. I recently reviewed the Troy Defense M5 9mm Carbine with one 10-round Glock magazine. For those states that ban such things, I assumed they pack their firearms with the smallest mag capacity possible. It was a relief to learn that this rifle came with not one, but two long magazines. Here’s the mag, from their site:

The mag isn’t only a 30-rounder, but it’s cheap and it works. For instance, I have nothing against polymer mags â I just have too many steel ones to start collecting polymer. And one big advantage â you drop the above mag, it bounces. No dings or dents. For $9 â from the factory, no less â you can stock up. In case you wanted metal or other types of mag, there are no worries. Most importantly, it shows six different styles and brands of magazines on its site, ranging from $9 to $25 and with a 5- to 45- round capacity.
The Gun Case
The gun case that the rifle came in was interesting. It has the company logo molded into the front and is pretty sturdy. It has two metal clasps at the front and full foam padding on the inside. Some folks don’t pay attention to the case their new gun comes in, but I do. I figured some folks may not have the cash to invest in a gun safe. So, the gun better arrive in a decent hard case, preferably one that’s lockable. But if your gun doesn’t come in one, here’s a list of good AR-15 cases.

The last long gun I reviewed came in a cardboard box, which offered little protection. This gun was different. As you can see in our reviews of handguns, some companies may put a mediocre product in a whiz-bang hard case. All else being equal, I’ll take a good-quality firearm in a cardboard box. For example, look at my excellent 1982-vintage S&W 629 8 â -inch-barreled .44 Magnum. It came in a cardboard box. If you don’t have a gun cabinet or safe, you need a decent hard case to put the gun in. Even something as minor as dust can wreak havoc with your scope or finely tuned action. Safety is also a concern.
I am doubly impressed with this gun and case because both seem to be of high quality.
Shooting the Rock River Arms LAR-15 BTB
On a cold day, I shot the BTB at my backyard range. I used the gun’s stock sights instead of adding a scope or red dot. Just wanted to see how it worked right out of the box. The fold-down or fold-up sights were, like most backup sights, both easy and not easy to pick up.
What do I mean? Those of you who have shot a rear-aperture-ring/front-post setup know what I’m talking about. The ring on the rear sight was typical. It did its job well, directing my eye to the front post. Here’s where it gets a bit sticky: like most all other front AR posts, the post is black and small. I’ve said before that sometimes my glasses aren’t the best at putting everything in focus. I had to hold my head at an angle to see the sights. Plus, the post is black.
On my Del-Ton AR, I used white liquid paper to make the front sight brighter and easier to see. While not the best, it was what I had available. I get it, this wouldn’t be a big deal if you are younger than 50 years old. If you were shooting at a range not surrounded on three sides by hills and trees. It’s pretty dark and gets increasingly so this time of the year. So, with all my lame excuses laid out, let me say that the gun did pretty well.
I ended up shooting some armor-piercing bullet ammo that I bought a few years ago and was glad that I saved it. They were pretty effective at punching holes in the steel plate. That was fun. For photos and a video of us perforating some fairly thick metal, check out my piece on the AR-50 .50BMG bolt action. That was a fun shoot.

Except for one type of ammo, the Remington plain-Jane “green box” 55-grain .223, I had good results with everything I shot.
I couldn’t get a single one of the .223 to “bang” and I’m not sure why, to be honest. I think it was the longer 5.56mm chamber not allowing the cartridge to seat deeply enough in the chamber for the firing pin to reach the primer. That really doesnât make much sense since the .223/5.56 cases are basically the same
I don’t know where else to look for a reason, however. I’d heard that not all .223 rounds may function in a 5.56mm rifle due to their chamber and the longer leade. Anyway, it was no big deal as I just shot other types. The 5.56 rounds mentioned above were fun and predictable.
The sights were good and the trigger was more than acceptable. The fit of the gun was fine as well. I enjoyed shooting it. I reloaded .223, but I refrained from shooting my loads in a test gun. They work fine and are accurate in mine.

What did I think of the Rock River Arms LAR-15? I liked it. You might think I’ve never met a gun I didn’t like, but that isn’t the case. This rifle was well-made, robust, and enjoyable to fire for me.

Here’s a close-up photo of one of the rounds I shot.
The Engineer’s Report
Before we end our look at the Rock River Arms LAR-15 rifle, I thought I might add some comments from one of my sons. He’s a manufacturing engineer at a regional automotive parts casting facility. I took the gun to him because I wanted him to see the rifle as an engineer. He’s also qualified as an AR fan. He owns at least one of his own and has taken it apart and modified it several times. He helped me build mine several years ago. Here are his observations.
The Case
He started with the case the gun came in. It uses rotating hinge pins instead of a tab to connect the halves. It has metal clasps on the front and stiff foam inside. The case will hold up to continuous use. It was also cleanly molded in terms of the logo on the top half.
The Rifle
- Fasteners: These are socket heads, not hex heads, and are of industrial strength.
- Handguard: Made of reinforced glass fiber and well-made. This is more expensive to make than plain plastic. It wears molds out quicker. Even the inside is well-finished, which it didn’t need to be.
- Magazine: The halves are well-matched, with the overall finish very well done. No molding lines are visible.
- Rails: The rails are threaded into flat metal T-nuts, not a plastic insert.
- Engraving: The lettering is clearly cut with no “fuzz” or rolled-over edges.
- Trigger components: MIM cast to precise tolerances. There’s not much evidence of post-processing.
- Overall metal finish: It’s very even with no “waves” or other anomalies.
- Threads: The threads for the stock and barrel weren’t overly sharp. There is no “chattering” evident.
- Bolt: He wasn’t sure if the bolt had been shot-peened, but it had been post-process finished. The bolt screws are from Fang Sheng Screw Company in Taiwan (YFS marked on the heads). This company’s products are built to either ISO 17025/9001/14001 or ISO/TS 16949 standards. They are very tough.
- General metal fit: No burrs or sharp edges â it had been blended very well. The radiuses had been hand-blended, most of them. There aren’t many tool paths, It’s very smooth with no snagging of fibers from a cloth.
As I said, he’s a shooter and knows of gunsmiths who have bought Rock River Arms rifles because of their quality.
What Compares to the Rock River Arms LAR-15?
Diamondback Firearms DB15 5.56 NATO 16″ Black
If you want similar specs for less, Diamondback Firearms’ DB15 is a great starter option. It costs over $200 less than the Rock River Arms LAR-15. For less, you are getting an accurate rifle with a comparable twist rate of 1:8. It’s also almost a pound lighter. You’ll be carrying a slightly lighter rifle and shooting almost the same ammo grains. This rifle also has a six-point collapsible and foldable buttstock. What it doesn’t have are sights, but you can install all kinds of optics in its free-floating M-LOK rail.
Smith & Wesson M&P 15T II
The S&W M&P 15T II is another alternative, albeit costing $400 more. It’s still relatively affordable for what it offers, so don’t be put off by the price. The proprietary M&P pistol grip with interchangeable palm swells is interesting. The flat-faced trigger is a nifty feature to have. With its full-length, free-float rail, you have a wide range of accessory options. The controls, other than the mag release, are ambidextrous. The barrel twist of 1:8 is also similar to the Rock River Arms LAR-15 and Diamondback DB15. If you can afford to pay more for premium features, check out the M&P 15T II.
Ramp Up Your Rock River Arms LAR-15
Aero Precision AR-15 Enhanced M-LOK Handguards 12″, Gen 2
Improve your rifle’s accuracy by swapping the drop-in rail for a free-float one. Aero Precision’s enhanced handguards are lightweight. The scalloped rails allow for a better grip. This is an M-LOK-compatible free-float handguard. With this, you can mount accessories easily onto your Rock River Arms LAR-15.
Rock River Arms AR-15 National Match 2-Stage Trigger
Another part you can upgrade for accuracy is the trigger. By converting the trigger to a two-stage one, you can ensure more precise shots. Note that a two-stage trigger isn’t necessarily a better trigger. Are you unsure about the two? Then check out this article differentiating the two trigger types. If you want to look at other trigger options, we do have a buying list for AR-15 triggers.
CVLIFE Red & Green Illuminated Scope
Are you shooting at farther distances or need the extra magnification? This scope can offer you both. Magnification is available from 2.5x to 10x, with a standard 40mm objective. Coincidentally, this is MeatEater’s favorite scope magnification. CVLIFE’s mount is durable, made from high-strength aircraft-grade aluminum. The manufacturer claims that their green multicoated lens has a higher light transmittance than scopes with blue lenses. The specs say that they’re for Dovetail mounts, but don’t worry as they can fit Picatinny rails just fine.
M & A Parts AR-15/M16 Flat-Top Scope Mount
If you are going to use a scope, you need a mount that can provide a secure attachment for it. This scope mount from M&A Parts is affordable without sacrificing reliability. Because it’s a one-piece mount, it provides a sturdy base that can withstand impact.
To Sum Up
Rock River Arms LAR rifles are some of the best AR-pattern guns you can buy. If you don’t believe me, ask anyone who works for the DEA, FBI, U.S. Marshals, or any one of thousands of satisfied civilian buyers. These rifles are tough and stand up well to abuse. They are accurate and made out of some very tough parts. I don’t think you could do much better. If you are in the market for an AR, I’d like to say that I was blown away by the price of the gun I tested. For slightly more than an $800 manufacturer’s suggested retail price (MSRP), you get a rifle that should last you a lifetime. One that you could still pass down to your kids. The actual real-world pricing starts at around $750. I don’t think you could do much better than that.
If you’re looking at more options for AR-15s, we have compiled all our AR-15 & AR-10 articles in one spot. We’ve spent hundreds of hours and thousands of rounds of ammo for our reviews, so I’m hoping they serve you well. As always, leave a comment below for all to read and then go shooting. Just stay safe.