The new tack-driving BT-3 from Rock River Arms performs as good as it looks.
How this AR-10 will have the bullseye begging for mercy:
- The BT-3 comes chambered in .308 Win.
- The rifled features billet aluminum upper and lower receivers.
- It's outfitted with a 20-inch fluted and cryogenically treated stainless-steel barrel.
- This is topped off with Rock River's .308 A2 flash hider.
- The BT-3's furniture includes a Magpul PRS stock and Hogue rubber over-molded grip.
- The fire control is Rock River's 2-stage trigger.
- The rifle weighs in at 12 pounds.
- The best grouping in testing at 100 yards was .935 inch with 155-grain Hornady TAP Precision.
Let me put this out there right away: I’m not a rifle shooter by trade. I like shooting rifles — it’s fun and it’s challenging — but I certainly don’t feel as though I’m capable of producing the level of accuracy today’s precision rifles are capable of delivering.
But that was the point: I’m a proficient pistol shooter and, as a professional firearms photographer, I know guns as well as anyone. Gun Digest Editor, Luke Hartle, had a brand new gun he wanted reviewed, and he wanted it reviewed from the perspective of a fairly novice precision rifle shooter looking to get into the game.
So, when I was tasked to review the new Rock River Arms BT-3 .308 Modern Sporting Rifle, I decided to meet the challenge head-on.
Assessing The Situation
My first task was to get acquainted with the rifle. The Rock River Arms BT-3 is a .308 modern sporting rifle, featuring Rock River Arms billet upper and lower receivers, fluted 20-inch cryogenically treated stainless-steel barrel, Rock River Arms .308 A2 flash hider, Magpul PRS stock, Hogue rubber over-molded grip, new lightweight M-LOK compatible 17-inch aluminum floated handguard with MS1913 top rail and a Rock River Arms 2-stage trigger. The rifle weighs in at approximately 12 pounds and is fairly easy to carry — but heavy enough to absorb recoil from the .308 Win. needed for precision accuracy at exceptional ranges.
For my scope, I wanted something powerful and sharp. I picked the SIG Optics Tango6 5-30X56mm riflescope with an illuminated MRAD/MOA reticle, and I mounted it on a SIG base and rings. As a rifle-shooting newbie of sorts, I wanted a scope that would mitigate my lack of rifle shooting experience. OK, I wanted a scope that would make me look good — and the Tango6 certainly didn’t fail me in that regard. It took me a bit of time to properly install and set up my scope and rifle for both length of pull and eye relief, but once I had it, I was ready to roll.
Range Tested, Shooter Approved
All that was left was to hit the range. I decided I wanted calm and shade: Spring in Arizona is often unpredictable and weather varies from wet and soggy 60s to hot and steamy upper 90s. I wanted to do this as “by the book” as possible, so waiting for calm winds was my only option.
I settled in on a steady concrete bench and set up my Caldwell “The Rock” rest. I’ve had this rest for more than 15 years and it’s still my favorite.
The first three shots with Remington 168-grain BTHP factory ammunition at 25 yards showed that I was 3 inches low and 1 inch to the right. I already knew that I didn’t want to shoot bull’s-eyes at 25 yards with a 100-yard zero in mind, so I made some minor adjustments and ran the target to the 100-yard mark.
I shot five-round groups at 100 yards with Remington 168-grain BTHP, Lapua 167-grain BTHP, Hornady 168-grain A-Max, Hornady 155-grain TAP A-Max, Hornady 110-grain TAP Urban, and Federal American Eagle 150-grain BTFMJ ammunition. At 100 yards, my groups were a bit to the right, but I was just looking for groups so I didn’t touch the scope. And the BT-3 didn’t disappoint.
I shot this rifle within my skill level, and I think I shot it well. My best 5-shot group was with the Hornady TAP Precision 155-grain A-Max Law Enforcement Ammunition, measuring .935 inch. I didn’t know I was capable of shooting like that, and especially not after a mere dozen rounds.
Think about that for a moment: As a new rifle shooter, I shot a sub-MOA group after pulling the trigger less than a dozen times. In the hands of a skilled rifle shooter, the groups from this rifle will shrink dramatically.
The Initial Takeaways
I was impressed, it’s as simple as that. The construction and fit of the rifle are among the best I’ve seen in years. Keep in mind that, although I don’t shoot a lot of long guns, I’m a professional firearms photographer and I recognize quality and attention to detail when I see it.
The fluted stainless-steel barrel pretty much proves that you don’t need a bull barrel to achieve precision on a rifle. The lightweight handguard is comfortable and has enough M-LOK slots to add whatever accessories you might need or want. The Magpul PRS Stock is one of the best stocks in the market for any precision rifle build; it was easy to set up and, after being set up, nothing moves and it retains its settings after a long day of shooting. These guns can quickly become complex, so I greatly appreciated the furniture being so user-friendly.
I was neither hot nor cold about the Hogue over-molded grip. It was comfortable, but I prefer a little bigger grip. Then again, this is the beauty of the MSR — it’s a completely modular system as long as the foundation is there, and the BT-3 is one heck of a foundation upon which to personalize a precision rifle build. The really nice thing about Rock River Arms is that you can order this specific rifle custom-made to your taste and requirements; you’re not stuck with a rifle only to purchase your favorite parts later.
Last but certainly not least, the trigger was the most impressive part of this rifle. Even though I’ve worked with lots of two-stage triggers in the past, this one was about the best I’ve had the pleasure of shooting. It made all the difference in my performance.
The Final Shot
My ultimate conclusion is that the Rock River Arms BT-3 is a winner for both novice and experienced precision shooters, though I would change a couple of the accessories.
I look forward to hitting the range again, and I’m certain that I won’t need to burn through too much more ammo before this rifle and I approach the ½-MOA mark together.
For more information on the BT-3, please visit: https://www.rockriverarms.com/www.rockriverarms.com
Editor's Note: This article originally appeared in the May issue of Gun Digest the Magazine.