In U.S. military parlance, DMR stands for Designated Marksman Rifle. The default chambering of the DMR is 7.62 NATO/.308 Win. The DMR originated to fill the effectiveness gap between issued combat rifles and sniper rifles. This middle ground is roughly between 270 and 650 yards. The DMR is closer to the sniper rifle versus combat rifle in terms of terminal ballistics, adjustable buttstocks, match triggers, match barrels, accuracy standards, magnified optics and accessories to facilitate long-range shot placement. The DMR is typically semi-automatic with detachable magazine capacity of 20 rounds or more. The M14 was the initial military DMR due to it already being in the logistic system and easy to adapt. Most would concede that better platforms are available. The Rock River Arms BT-3 Precision and Daniel Defense DD5V3 are both good examples.
Daniel Defense DD5V3 versus Rock River BT-3
Accuracy potential of a quality AR-type weapon is often on par or superior to a bolt-action. The DMR has come into its own within the military and has expanded rapidly into law enforcement use. This is due to a variety of factors including accuracy and the need for better ballistic and terminal performance than rifles chambered in 5.56mm can provide. Lastly, not to be discounted is the ability to have 7.62 NATO firepower in a high-capacity AR platform if unexpectedly engaged in a close melee with a need for multiple rounds sent downrange quickly. 7.62 NATO potency in terms of ballistics and terminal effect makes it a favorite among our troops, law enforcement personnel and security-conscience private citizens.
Rock River Refinement
Brothers Mark and Chuck Larson founded Rock River Arms (RRA) in 1996. The Larson brothers combined 40 prior years of experience in the firearm business into RRA. Rock River’s quality control was quickly rewarded within only a few years of emerging on the AR scene. RRA’s operating methodology was quickly brought to the forefront by winning contracts to provide AR rifles to DEA and FBI law enforcement agencies. This has been followed with multiple other procurement deals with federal, state and local law enforcement entities.
Rock River Arms, as is its custom, offers numerous configurations of the BT-3 platform, with one sure to suit a prospective buyer’s needs, whether an individual, unit or department. The BT-3 Precision comes with a fluted 18-inch cryogenically treated barrel. The BT-3 Precision features an extended, free-floated, 17-inch M-Lok forend rail system. Being direct-impingement versus piston driven assists the rifle in maintaining balance and accuracy.
RRA’s goal with the BT-3 is to wring the most reliability and accuracy out of Eugene Stoner’s design. These two objectives are often at odds with each other. The tight tolerances associated with accuracy can hinder reliability if not applied properly. By improving fit and finish, including the use of a billeted lower receiver with the BT-3, RRA sets itself apart from the majority of AR manufacturers in existence today. (rockriverarms.com)
Daniel Defense DD5V3
If you want it done right, do it yourself. This might be the unofficial motto for all Daniel Defense endeavors since arriving on the AR scene. The Daniel Defense DD5V3 model evaluated here is an embodiment of this statement. Marty Daniel decided in 2000 that the AR market was ripe for someone to introduce quality aftermarket accessories such as sling adaptors, railed forends and more. This is probably hard to fathom in the current 2020 situation with a plethora of ancillary AR products available. It was a natural leap for Daniel Defense to produce complete AR rifles starting in early 2009.
This in-house production allows DD a high degree of quality control and frees the company from overreliance on suppliers. Daniel Defense makes its own barrels, upper receivers, lower receivers, receiver extensions, bolt carriers, bolts, carrier keys and gas tubes. The company proofs and magnetic particle inspects every bolt to guarantee reliable performance. Daniel Defense even goes so far as to produce its own lower parts kits.
Heart of the Rifle
A key component to the Daniel Defense AR reputation for accuracy is the Chrome Moly Vanadium steel cold-hammer-forged barrel. A Daniel Defense hammer-forged barrel starts its life as a short steel blank with a hole drilled down its center. The blank is threaded over a piece of hardened steel mandrel that is the exact dimensions of the rifle’s bore. Big hammers then pound the blank onto and around the mandrel until the barrel is 16 inches long (or whatever is specified) and has the appropriate contour. The process makes for a very dense barrel that is ideally suited to a high-round-count carbine. The DD machinery doing this work at the company’s Black Creek facility has been installed on vibration dampening flooring and isolation springs so as not to impact other delicate machinery surrounding it. Daniel Defense technicians follow detailed proprietary quality control methods with each barrel produced.
The DD5V3 builds upon the foundation established in previous DD 7.62 AR-style rifles. Suppressor use is expanding. An adjustable gas block on the DD5V3 is conducive for shooting suppressed or unsuppressed. Along these same lines, a Grip-N-Rip ambidextrous charging handle with anti-gas features is standard. The DD bolt carrier group is DLC-coated, simplifying maintenance and reliability in adverse conditions. Daniel Defense’s bolt carrier has enhanced extractor geometry and dual ejectors for hell-and-back reliability. Daniel Defense’s attention to detail is typified by the innovative 4-Bolt Connection system, which offers a rigid connection between the 16-inch DD barrel and the upper receiver, promoting accuracy. (danieldefense.com)
Optic Enhancements
To exploit the versatility of the Rock River BT-3 and Daniel Defense DD5V3, Vortex Razor HD Gen III 1-10×24 FFP and Nightforce NX8 2.5-20X50 F1 optics were mounted. Both offer a low-power setting for quick target acquisition at close range, yet a turn of the knob allows for longer or precision shots as the mission dictates. Both rifles’ Picatinny, flat-top receivers allow for one of the sturdiest and most versatile scope-to-rifle connections available. Users will need to judge which optic best satisfies their individual needs. Variable optics are becoming more the norm in military and law enforcement circles, especially as available power ranges expand. The Vortex 1-10x and Nightforce 2.5-20x are excellent examples of this.
Most have no idea what they are missing in terms of rifle optics offered by Vortex and Nightforce. Each produces some of the most diversified, high-performing lineups of scopes on the market. Many in our community hold strongly to preconceived notions regarding optics choices. One must get past these comfortable beliefs to truly appreciate what another product might offer. The low-magnification setting with wide field of view, edge-to-edge clarity and illuminated reticle options allow for extremely fast, accurate target acquisition. Both the Vortex and Nightforce can handle close-quarter situations and much longer shots with only a quick turn of the magnification dial.
Range Observations
Both .308 rifles performed superbly in terms of accuracy, reliability and handling. Each rifle spent time with Nightforce and Vortex optics mounted. Various .308 loadings from Remington, Sig Sauer and Federal provided the basis of accuracy tests. No ammunition, including full-metal jacket ammunition, generated greater than 1.75-MOA accuracy levels. Both direct-impingement ARs proved reliable throughout this evaluation with more than 350 assorted rounds each sent downrange. The 16-inch DD5V3 barrel sacrifices approximately 20 to 30 fps to the RRA BT-3’s 18-inch tube. For me this is negligible considering accuracy was equal.
The Rock River BT-3 initial group was fired with Sig Sauer Elite 168-grain BTHP. Three rounds nestled into a 0.75-inch cluster at 100 yards. I figured this would hold sway showing the Rock River as the more accurate rifle. The Daniel Defense answered the call by producing slightly better accuracy with this same load! This pattern continued throughout testing with one rifle better with certain loads and vice versa. Each produced above average accuracy compared to my previous experiences with AR-10 platforms.
Shooting Zombies
Echo Valley Training Center has been hosting the Hesco Zombie Invitational for the last six years. The Zombie Invitational is a precision rifle, pistol and shotgun match with a zombie theme. A participant is tasked with carrying all weapons, ammunition and supplies for the entire day of activities—no returning to vehicle or campsite to top off ammunition or resupply. We all know that a round to the brain is the best way to deal with a zombie, thus, precision is the key for all the timed stages encountered.
Both the Rock River Arms and Daniel Defense AR-10 rifles were evaluated using this format. There is no better way to get a feel for a weapon than humping it around all day, then being timed in front of your peers while engaging targets. As expected, the BT-3 and DD5V3 were ideal for the longer-range engagements where hitting a 4-inch round target is no easy task. The BT-3 and DD5V3 both handled the CQB stages without issue.
Little nuances are what separated each rifle. For example, the Rock River Arms two-stage trigger was more user friendly, especially when shooting from the bench or prone for accuracy purposes. The Daniel Defense DD5V3 exhibited a smoother recoil impulse. Handling was equal, with each rifle’s furniture conducive to controlling/manipulating the weapon. Weight was only a few ounces different, even with the BT-3’s 2-inch longer barrel. The Daniel Defense DD5V3’s adjustable gas block is a great feature to adapt to various .308 loads, not to mention if suppressor use is contemplated.
All-Around Performers
The case can be made that the Rock River Arms BT-3 and Daniel Defense DD5V3 allow expansion beyond DMR supporting roles and are prime weapons of choice in their own rights. Both serve as a benchmark for performance in the precision role as well as general-purpose tactical rifles. The 7.62 NATO chambering has power to spare. Rock River Arms and Daniel Defense have created rifles that are imminently adaptable to modern tactical situations.
Rock River Arms BT-3 Specs
- Caliber: 7.62 NATO
- Barrel: 18 inches
- Overall Length: 36.5 to 39 inches
- Overall Weight: 8.5 pounds (empty)
- Stock: RRA six-position
- Sights: None
- Action: Semi-automatic
- Finish: Black
- Overall Capacity: 25+1
- MSRP: $1,550
Rock River Arms BT-3 Performance
| Load | Velocity | Accuracy |
| Federal 168-grain Match | 2,627 | 0.75 |
| Remington HTP 168-grain TSX | 2,605 | 0.75 |
| SIG Sauer 150-grain FMJ | 2,735 | 1.25 |
| SIG Sauer 168-grain OTM | 2,640 | 0.66 |
Daniel Defense DD5V3 Specs
- Caliber: 7.62 NATO
- Barrel: 16 inches
- Overall Length: 33.5 to 37 inches
- Overall Weight:8.3 pounds (empty)
- Stock: DD extendable
- Sights: None
- Action: Semi-automatic
- Finish: Black
- Overall Capacity: 25+1
- MSRP: $2,449
Daniel Defense DD5V3 Performance
| Load | Velocity | Accuracy |
| Federal 168-grain Match | 2,605 | 0.66 |
| Remington HTP 168-grain TSX | 2,578 | 1.00 |
| SIG Sauer 150-grain FMJ | 2,709 | 1.25 |
| SIG Sauer 168-grain OTM | 2,613 | 0.50 |
This article is from the October-November 2020 issue of Tactical Life magazine. Grab your copy at OutdoorGroupStore.com.
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