The ROCK RIVER ARMS LAR-15
by Kim Foster

I am not a professional writer. This rifle was not lent or given to me so that I would say good things about it. I purchased it at a local gun store. I had been looking for a 16 inch-barreled flat top AR for some time. My reason for selecting Rock River Arms was partially because they have an excellent reputation and because I was impressed with the fit and finish of this particular rifle. Rock River produces several variants. The one I selected is the Tactical CARA4. It is a flat top upper with a 16 inch barrel, 1-9 twist, that does not have the cut-out for the M203 grenade launcher. Rock River's barrels are made by Wilson Tactical. It has R4 handguards, Rock River's National Match two stage trigger on the lower and a tactical (A3) telescoping stock.

The rifle came with a large, hard plastic case. The inside of the case is molded so that placing the rifle into it requires separating the upper and lower halves and prohibits any type of optic from remaining on the upper. Not very useful. Instead of an owner's manual, Rock River sent a pocket version of the Army Operators Manual TM-9-1005-319-10. It is noted on the cover that this version supersedes the previous copy dated August 1986. Since I purchased the rifle in July ‘06, I was relieved to know that (tongue-in-cheek humor). The manual has good information and illustrations on field stripping and cleaning for those unfamiliar with AR/M16 rifles. However a good portion of the manual deals with burst fire and attaching the M203, things that have no bearing on civilian use.

One thirty-round magazine was included. It had a thin, black plastic follower that would get wedged in the magazine body if it was depressed unevenly. In my opinion these type of followers are unreliable and unacceptable for defensive use. I replaced it with a Magpull self-leveling follower. Considering the money that Rock River is getting for their rifles these days, it wouldn't hurt them to include a better magazine follower.

The rifle was almost dripping with some sort of rust inhibiting packing oil, which was a good thing. The first thing I did was disassemble, clean and inspect it. The fit between upper and lower was very tight. In fact all the tolerances appeared very close. When I inspected this rifle in the store, I noticed that the staking indentations on the gas key did not appear very deep. This concerned me because if the bolts securing the gas key to the bolt carrier become loose, the rifle will not function. I looked at three more Rock River LAR's in the store and they were all staked in an identical manner. So far, it has not been a problem.  This rifle has the two-stage match trigger and it is a much appreciated improvement over standard AR triggers. A leaflet included with the rifle, the only Rock River literature to come with the gun, stated that the barrel had been lapped at the factory and no break in procedure was required. Although I had planned to break in the barrel, I decided to forgo that.

Sighting in and groups

Sighting in at 50 yards with the iron sights was simple. The sights required very little movement from mechanical zero. The temperature was close to 100 degrees, somewhat uncomfortable. The majority of my 3 shot groups were under ½ inch at 50 yards. With an average of .44" measured with a digital caliper.

I mounted an EOTech 512 HWS on the Dominator rear sight base that came with the rifle. The Dominator has a fixed rear sight with the standard A2 apertures, and provides a slightly raised platform for the EOTech. This allows the iron sights to co-witness in the lower third of the EOTech window. The EOTech's reticle is advertised as a 1 MOA dot inside a 65 MOA circle, an excellent reticle pattern for CQB out past 100 yards. (editor's note--how can combat out beyond 100 yards be considered "close quarters battle?) Although a one MOA dot should cover approximately one inch at 100 yards, mine covered about a three-inch circle. The sight came with an owner's manual, batteries (2 AA), two cross bolts for mounting, a large wheeled thumb nut-style bolt for quick detaching in the field, and a hex head bolt with Allan wrench. Since the idea behind the Dominator base is having the back-up iron sights (BUIS) co-witness through the EOTech window, I used the hex bolt. The Dominator base is specifically advertised for use with the EOTech, however the cross slot in the base was quite a bit wider than it needed to be and I'm sure the EOTech will not retain its zero if removed. The windage and elevation adjustments require a small coin or flat head screw driver and are graduated in ½ MOA increments, according to the manual. I measured the distance the point of impact (POI) moved during adjustments and it was about 1 MOA per click instead of the advertised ½ MOA. This not at all unusual as I‘ve found only the most precise optics (read expensive) actually provide the advertised graduations. The important thing is consistency, and the EOTech adjustments were consistent. Zeroing at 50 yards required a lot of downward adjustment but the sight responded appropriately. When I began shooting at 100 yards, I noticed my point of impact started wandering about two inches to the right.  I'm not sure why it occurred but was easily corrected.  The front sight tower is plainly visible in the EOTech's window, however once you learn to focus on the reticle you don't even notice it. I did some low light shooting after dark. The combination of the EOTech's circle dot reticle and a Streamlight M3 mounted to the bottom of the hand guard is the cat's meow for low light shooting at CQB distances.

A couple words on the Streamlight M3. They don't have the best reputation for durability but I've shot with mine quite a bit, using a Glock 23, AR's and a Mossberg 12 gage and it has held up and performed fine.

When I bought the rifle, I traded the 6 position collapsible stock for a Vltor mod stock. It locks up firmly and I don't feel the vibration of the buffer spring, unlike some cheaper collapsible stocks I've used in the past. I bought a rubber slip-over butt pad for the Vltor and found that it greatly enhances the shootability of collapsible stocks. The Vltor has two tubular battery storage compartments along its axis. I don't find them particularly convenient or useful but it does make a nice cheek rest.

Shooting at 100 yards

Accuracy at 100 yards was very good. Numerous three-shot groups fired from a bench and spanning several days averaged 1.18 inches with Federal American Eagle 55 grain FMJ. Black Hills 69 grain BTHP averaged 1.09 inches.

I wanted to attach an accessory rail to the bottom of the hand guards for use with a weapon-mounted light and a vertical for-grip. The rail that I had used with my Colt wouldn't work because the studs on the rail would not match up with the holes in the bottom of the R4 handguard. The R4 has a slight oval shape and a slightly larger diameter than standard CAR handguards. I phoned Rock River and spoke to a Tech support person. Although polite, he didn't have an answer for my problem. He did give me the web address of a company he thought could help. They didn't have exactly what I needed but did lead me in the right direction. I ended up getting a universal rail by Falcon that matched adequately. To remove the handguard I used one of the new handguard removal tools that have become popular. They take all the pinching, cramping and sweating out of removing and installing hand guards and are well worth the money. The design is so simple, you wonder "why didn't I think of that?".

Vertical foregrips are a current fad in the tactical community. I've been using one for a while now but I can't say I really like them or find them of much use. If you are shooting burst or full auto, I think they help fight muzzle climb but in semi-auto rifles I don't think they contribute a lot, other than making some weapon-mounted lights easier to operate.

In conclusion, I'm very pleased with this Rock River rifle and would highly recommend Rock River to anyone looking for a top quality AR.  (2 Oct 06)

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