Gun Digest RRA Elite Operator-2 October 2011 Review
Gun Digest - October 2011 Review
Rock River Arms Elite Operator-2

Rock River Arms, Inc. is a manufacturing
company based in Colona, Illinois.

RRA manufactures firearms and parts and accessories for M1911 pistols and AR15/M16 type rifles in .223/5.56 & AR15 9mm. The company enjoys a solid reputation in the firearms industry. RRA was awarded a contract with the Drug Enforcement Administration to manufacture a new-issue AR15 carbine after they beat several high profile manufacturers in strenuous qualification testing.

The DEA subsequently purchased a substantial number of RRA carbines in 2003.

Rock River Arms is owned and operated by brothers Mark and Chuck Larson. Between them, the Larsons have almost half a century of gun making experience, with emphases on both semiautomatic pistols and gas operated self loading rifles. Indeed, the brothers' collective resume reads like a who's who of the American precision firearms industry: Between 1981 and 1991 the Larsons worked at Springfield Armory, Inc., where Mark was the head armorer. From Springfield Armory, the Larsons went into partnership with Les Baer to form Les Baer Custom, and produced some of the finest custom 1911 style pistols that have ever been seen on the US market. Parting ways with Les Baer in 1993, the Larsons began to build AR-15 type rifles for Eagle Arms in Coal Valley, Illinois. At around the same time, they began their own venture, Tolerance Plus (the name was later changed to Rock River Arms), producing custom 1911 pistols. The Larson brothers severed their connection with Eagle Arms in 1997 when that firm moved to Geneseo, Illinois. At the same time, Rock River Arms began to build AR-15 style rifles, with a commitment to producing the highest quality, most accurate AR's on the market.

Every major component of a Rock River AR15 starts out as either bar stock or a forging. Upper and lower receivers are made from forged and milled mil-spec 7075 T6 aluminum alloy that is then hard anodized to a surface hardness of 70 on the Rockwell scale. Lower receivers are held to extremely tight tolerances to ensure compatibility with the widest range of uppers possible. But that's just the start of the process. After final machining, each receiver is carefully polished to remove dings, scratches, and other small imperfections left over from the forging and milling processes. Once polished to a perfect mirror sheen, the receivers are then sandblasted and sent out for anodizing. This polishing step is unique, and is why minor receiver imperfections, such as those normally found in front of the magazine well, are not encountered on Rock River guns. Smaller parts, like the bolt stop, safety, and trigger components are investment castings made from 8620 steel that are case hardened to between 89 and 92 Rockwell.

Every Rock River Arms rifle features a 1:9" (1:8" in the DCM competition rifle) button rifled barrel made by Wilson Arms. All barrels are made from high grade chrome-moly steel. Each barrel is air gauged prior to assembly, and any that do not meet the most stringent criteria are rejected.

While the chambers of the rifle and the carbine that were the subject of this review were cut to SAAMI .223 Remington specifications, in the future all carbines will feature chambers cut to 5.56mm NATO specifications. After installation, the barrel's feed ramp is highly polished and contoured into the upper receiver, thus eliminating the common " step" between the barrel extension's feed ramp and the upper receiver that is found on most AR type rifles. As a result of these ministrations, Rock River Arms claims significantly improved reliability with all types of 5.56mm ammunition.

Rock River Arms laser engraves all upper receivers.
Rock River Arms Laser Engraving

All factory-built upper halves and complete rifles are engraved with RRA's trademarked logo.

You pay for 100% Rock River Arms, you should get 100%. We deal square and don't substitute quality RRA parts for non RRA. If it doesn't say Rock River Arms...~caveat emptor


Rock River Arms stamps each barrel as to Chrome-Lined, Moly or other designation.

Hidden beneath the hand-guard just forward of the receiver. RRA marks each barrel. Unfortunately this mark is impossible to see without disassembly. An easy way to determine 100% Rock River is to check the configuration label on the end of the blue Rock River Arms safe-case.

If you pay for Chrome-lined, make sure you get it!

Rock River Arms Barrel Codes
"C" indicates chrome-lined

Three characters side by side over the chamber.
First Character: N or W...N for NATO chamber or W for Wylde
Second Character: 8 or 9...8 for 1:8 twist and 9 for 1:9 twist.
Third Character: A, S, or C...A for moly (chrome-moly Alloy), S for Stainless, and C for Chrome-lined alloy.

New Codes:
The actual base part number from our parts system/catalog, located over the chamber. These are the most common. Unless indicated otherwise, all stainless barrels are 1:8 twist and all moly barrels (chrome-lined or not) are 1:9.

All 16" moly barrels have a NATO chamber, while the 20" moly and all stainless barrels have a Wylde chamber.

200 =moly CAR
200CL =Chrome-lined CAR
202 =moly R4
204 =Chrome-lined R4
205 =Chrome-lined light-weight R4, 1:7
206 =Stainless CAR
208 =16" varmint
210 =moly Mid
212 =Chrome-lined Mid
215 =Stainless Mid
218 =18" varmint
219 =Chrome-lined light-weight R4, 1:9
220 =moly Std (rifle)
221 =Chrome-lined Std (rifle)
222 =Stainless NM(rifle)
223 =Stainless NM (rifle), unthreaded
226 =20" varmint
228 =24" varmint (1:8)
229 =24" varmint (1:12)

There may be "S" & "C" after the numbers. The "S" is for stainless and the "C" is for chrome-lined.


Why Rock River Arms should be your weapon of choice for your AR15 purchase.

For a rifle you will enjoy shooting for years to come, a few weeks of extra time to custom build your rifle right is well worth it. Unlike other major AR-15 manufacturers, RockRiver Arms does not build rifles in a assembly line process. Instead a skilled armorer is dedicated to building strictly the lower assembly and another armorer the upper assembly. After the upper and lower assemblies are completed they are fitted together by yet another armorer. Once the rifle is fitted the barrel is lapped and additional touches made. The rifle is then sent to the range and test fired for fit and mechanical function. After the rifle has passed the test firing it is returned to the factory where is is cleaned, oiled and packed for shipment to the dealer. 

Everyone has their own measure of what quality is. In my observations Rock River Arms exhibits superior workmanship in fit and finish. While fit and finish is not the end all to any weapon, it does illustrate an attention to workmanship detail by Rock River Arms. An attention to detail that sets Rock River Arms apart from other AR15 manufactures.

Recently I took the time to compare a 16" Rock River Arms Varmint to a like 16" Varmint made by another name brand AR-15 manufacturer. I decided to take a couple of measurements and illustrate what I consider a superb metal to metal fit on the Rock River Arms Varmint as compared to the competition.

2k Gap

Measuring a popular name brand AR15 for upper and lower fit. The competitors receiver to lower fit was measured by inserting a machinist Leaf Gage which revealed a .002" of an inch space between the upper and lower assemblies. This level of gap or space between the upper and lower will effectively allow you to see light between the upper and lower components. Further, the gap will allow enough space for the upper and lower to rock between each other and not give a snug fit. In measuring the Rock River Arms 16" Varmint there was no space or gap between the upper and lower. In measuring a wide assortment of various other Rock River Arms rifles the tight fit consistency was apparent throughout.

2k Gap 2
Side view of popular name brand AR15 and .002" gap

Rock River Arms Perfect Fit

Rock River Arms, a perfect metal to metal fit between the upper and lower assemblies.

2k Gap 3

Try the fit test. Grab the stock with your left hand and the forearm with your right or if a tactical stock, hold to the lower receiver grip. While holding the stock or grip firmly with your left hand, twist the upper with your right hand to determine if you have any loose fit between the upper and lower. Does the gap between the upper and lower open and close as you rock the upper back and forth? If the upper moves independently of the lower, there is not a tight metal to metal fit between the upper and lower receiver.



Rock River Arms #1: DEA rifle of choice!


The initial phase consisted of:

1. Inspection and measurement to ensure the submission conforms to

2. Function testing, which consisted of five rounds from each of six

3. Accuracy/Dispersion/Velocity Test:

--Three randomly selected carbines would fire three 5-shot groups at
100 yards from machine rest.

--The same three carbines would be hand-fired from bench rest for three
5-shot groups at 100 yards. The largest hand-fired group would be
eliminated. The remaining five groups were averaged and must not
exceed 4".

--10-shot strings were chronographed and had to average no less than
2,350 fps.

4. Abuse Test

--Parts interchange test: three carbines were field stripped and major
component parts randomly interchanged, reassembled and each must fire
ten rounds each of both duty and training ammunition without

--Extreme Temperature Test:

(A): Two properly cleaned and lubricated carbines were loaded to
capacity with DEA/FBI service ammunition and exposed to a temperature
of -20 degrees F for one hour. Then it was taken from the cold and
immediately had to fire the complete magazine at room temperature.

(B): The same two carbines were allowed to dry and stabilize to room
temperature, reloaded and subjected to a temperature of +120 degrees F
for one hour.

Following the high temperature they had to be fired immediately.

Interestingly enough stoppages during the extreme temperature testing
would not eliminate the sample if the shooter could clear them with
customary immediate action drills.

c: Drop Test: Two carbines were loaded with a primed cartridge case
plus a full magazine and, with the safety on, dropped from a height of
four feet with:

sights down, muzzle down, muzzle up, right side, left side and squarely
on the bottom. After each drop the primed case was inspected. If it
fired the test was repeated and a second firing constituted failure of
the test. Following the drop testing the carbine had to fire 20 rounds
of service ammunition without malfunction.

d: Throw Test: Two carbines were loaded with a primed cartridge case
plus a full magazine and thrown from a height of four feet over a
distance of 15 feet to land once on the right side and again on the
left. The carbine must not fire the primed case or permit the magazine
to fall out. Following the throwing the carbine must fire 20 rounds of
service ammunition without malfunction.

e: Salt Water Immersion and Corrosion Test: A carbine lubricated
according to the manufacturers specification was immersed in a saline
solution resembling sea water for five minutes, removed and shaken 15
seconds to remove water and allowed to sit for two hours at
temperatures between 68-78 degrees at a relative humidity of 30 to
50-percent. Following that time it was field stripped, rinsed with tap
water, drained and held for 24 hours. At the end of that period it
had to fire 20 rounds of service ammunition without malfunction.

f: Sand Exposure Test: One carbine is cleaned and lubricated, loaded to
capacity and placed on its left side in a box filled with a mixture of
50-percent each of coarse "road" sand and fine "play" sand. Sand was
scooped to completely cover the carbine. It was then removed from the
box, shaken for 15 seconds and had to fire all rounds. Malfunctions
would be "noted" and must be clearable by immediate action drills.