Rock River Arms All Terrain Hunter, by Thomas Christianson

The Rock River Arms All Terrain Hunter (ATH) is an AR-platform rifle optimized for hunting. It is attractively styled and beautifully machined. I found it to be accurate and reliable in my testing, and was especially impressed with the outstanding trigger. With a manufacturer suggested retail price of $1,425 it is an attractive choice as a mid-range AR-platform rifle.
I really like AK-platform rifles chambered in 5.56mm. I appreciate the rugged reliability of the AK platform matched with the flat trajectory of the 5.56 cartridge. So to some extent, this review is an AK guy’s reflections on an AR. It is not that I have anything against ARs per se, but handling an AR always feels a little like speaking in a second language in which I am not fully fluent.
In spite of this, when I received a press release from Rock River Arms about the All Terrain Hunter, I was really interested. Among other attractive features, the 18-inch free-floating heavy stainless steel barrel is guaranteed to provide 3/4 MOA accuracy at 100 yards, the trigger guard is optimized to accommodate gloved fingers, and the rifle is chambered in .223 Wylde so that it can safely and effectively chamber both .223 and 5.56mm ammunition. I asked Rock River Arms if I could borrow a sample for testing and evaluation, and they were kind enough to agree.
When I picked up the ATH at my FFL, the first thing that struck me was the excellent case. Many rifles, even very expensive rifles, come in a cardboard box. When a rifle comes in a case, the plastic is often so flimsy that it is not much better than cardboard. But Rock River Arms does an excellent job of packaging the All Terrain Hunter. The case is durable, well padded, and is large enough to accommodate the rifle even after optics are mounted.
As I opened the case, the first two things I noted about the ATH were that it is attractive, and that it was generously oiled. The attendant at my FFL who was assisting with the transfer grabbed a rag right away and went to work on the outside of the rifle. It would have been extremely messy to handle the ATH without a good initial rubdown.
I like the look of stainless steel in general, and so found the barrel of the ATH to be is a thing of beauty and a joy forever.
The magazine that came with the rifle was uninspiring. Consumer versions of the ATH are advertised to ship with a 20-round steel magazine. The test sample I received came with a badly scuffed aluminum magazine.
Along with the rifle and magazine, the case contained a plastic bag with an Owner’s Manual, a yellow plastic empty chamber flag, a card with assembly instructions, a card warning against feeding rounds in through the ejection port, and a card warning that the firearm may not be legal in all jurisdictions.
I started to familiarize myself with the rifle by reading the entire 52-page Owner’s Manual. The typeface was small enough that I needed to wear my bifocals in order to complete this task comfortably.
One unexpected piece of advice from the manual concerned how to handle a hangfire. That advice was to wait 15 minutes with the rifle pointed in a safe direction before clearing the chamber. This was the longest recommended wait period before clearing a faulty round that I had ever heard. This did not make sense to me at first, but continued reading brought additional context. In general, they recommend only clearing a live round within 10 seconds of chambering, or after 15 minutes, due to the risk of rounds cooking off in a hot chamber. Since 10 seconds is too soon to safely clear a hangfire, it is recommended to wait the full 15 minutes instead. Most other rifles are not expected to put out a high enough volume of fire for the cooking off of rounds in a hot chamber to be an issue.
The manual also recommended using only American-made, brass-cased ammunition. I intended to flout this recommendation, since firing steel-cased ammunition is one way to get a sense of the reliability of a rifle during a limited testing period.
The rifle comes without iron sights. The full-length rail on top of the barrel shroud is more than long enough to allow for the installation of aftermarket iron sights, or pretty much any other optics the owner may wish. I am just old enough to prefer for my rifles to come with iron sights pre-installed.
I was also interested to note that the barrel comes lapped from the factory, so that there is no need to break it in.
The manual recommends cleaning the rifle prior to firing it for the first time in order to remove excess shipping oil. This is also an excellent way for a new owner to begin to familiarize himself with his new rifle.
Disassembly involved separating the upper and lower receivers, removing the changing handle and the bolt carrier, removing the firing pin from the bolt carrier, and removing the bolt from the bolt carrier assembly.
Everything was coated with a generous coating of oil. I wiped away excess oil from all accessible surfaces; cleaned the bore, chamber, and bolt assembly parts with solvent, and then applied a thin film of CLP to the various parts. I then reassembled the ATH.
Throughout this process, I found the rifle to be a well-machined and aesthetically pleasing piece of machinery.
I mounted a Leupold VX-Freedom 3-9X40 scope on the rifle.
The medium-height rings that I initially used were a little too low. I had a cheap scope on another set of rings that were slightly taller, so I played musical scopes and rings. I removed the Leupold scope from the medium rings, the budget scope from the taller rings, and a horrible scope from a pellet gun from its rings. I then placed the Leupold scope in the taller rings from the budget scope, the budget scope in the rings from the pellet gun, and put the horrible scope aside for disposal. The taller rings were exactly the right height for the Leupold scope on the ATH. The operator buttstock of the ATH gave an excellent cheek weld. The budget scope on the pellet gun is a story for another day.
I then determined the proper eye relief for the Leupold scope, leveled the rifle and scope, tightened the rings evenly, and focused the scope. This process is described in more detail in my November 10, 2020 review of the Leupold scope in SurvivalBlog.
I set a group of nine targets against the backstop of the range behind my pole barn. I set up a table at the other end of the range, and put a lead sled on the table. I used the lead sled, not because I expected any issue with recoil from the ATH, but because it provides such a wonderfully stable shooting platform.
I then placed the ATH on the lead sled, chambered a single round, and fired at a target. My first reaction was surprise at the excellence of the trigger. It was so smooth and crisp that the rifle seemed to fire just at the thought of squeezing the trigger.
The first shot was about 3 inches low and about 4.5 inches to the left of the center of the target. Over the course of the next few groups, I was able to adjust the scope so that the groups were striking the center of the target.
I gave the rifle a bit of a torture test by firing steel-cased ammunition. I used TulAmmo 55 grain FMJ, TulAmmo 62 grain FMJ, TulAmmo 75 grain HP, TulAmmo 62 grain HP, TulAmmo 55 grain HP, and Wolf Military Classic 62 grain SP. The ATH chambered and extracted every round with 100% reliability. It liked the 62 grain bullets best, with the Wolf ammo providing the best groups of the various 62 grain offerings. I was not surprised, as I have previously experienced surprisingly good groups using steel-cased Wolf ammo.

FULL STORY HERE