We are seeing a trend of new rifles being introduced for the suppressor-savvy shooter. Some of the rifles are lighter, some aren’t. Most, however, do have threaded muzzles. Many have shorter barrels, keeping your rifle at a reasonable length, even with the suppressor attached. We selected two long guns of this type for review. The first is a Savage Arms Model 110 Tactical 57770, $663. A solid 8-pound rifle, the Model 110 Tactical features a medium-profile 18-inch barrel, an embedded aluminum chassis, and is adjustable via inserts for comb height and length of pull. Our second choice is the new Christensen Arms Ridgeline Scout 1739966, $2100. Weighing in at a feathery 5.9 pounds, the Christensen features a carbon-fiber-composite stock mated to a 16-inch carbon-fiber-wrapped stainless-steel barrel. Both were chambered in the relatively new 6 ARC (Advanced Rifle Cartridge) rifle round.

The 6 ARC Round

We readily acknowledge that, all other things being equal and up to a reasonable maximum, the longer the barrel on the rifle, the more complete the powder burn will be, resulting in higher velocities. Much of the testing and most of the results you read in manuals is derived from firing a cartridge from a universal receiver attached to a 24-inch barrel. Your barrel being shorter can quickly explain why your velocities don’t equal that listed on the box of your favorite bullet. We have also noted in our testing that medium to small cartridges, loaded with correspondingly less powder, may not need as long a barrel to achieve optimum velocity. They may even benefit from a shorter, stiffer tube. Both are great reasons we decided to test these abbreviated barrels with the new 6 ARC from Hornady.

The 6 ARC was originally de­signed by Hornady in response to a request from the Department of Defense and certain special groups in the agency. The goal was to optimize the energy and accuracy that could be projected from a standard AR-15/M4 platform and magazines for that rifle with, again, standard dimensions. In 2020, Hornady introduced the 6 ARC to no small fanfare and an ad campaign that unfortunately coincided with the onset of Covid-19. To say the least, details about the new cartridge did not stay front page very long.

The Hornady engineers and ballisticians produced a new cartridge with substantially better muzzle energy than the 5.56 in current usage. For example, Black Hills Ammunition lists its outstanding 77-grain MK 262 Mod 1 5.56 ammo as generating just short of 1300 foot-pounds of muzzle energy. With our rifles and factory Hornady ammunition, the Hornady 108-grain ELD-Match 6 ARC ammo topped 1600 foot-pounds, a 23% increase over the 5.56 round. According to our Applied Ballistics Mobile app, the Black Hills MK 262 5.56mm ammo stays supersonic (where bullet flight is still stable and predictable) to about 1050 yards and maintains 1000 foot-pounds of energy (the minimum suggested for deer) to about 150 yards. The 108-grain ELD-M recorded just under 2600 fps out of the Savage 110, resulting in over 1600 foot-pounds energy, with bullets that stayed supersonic to about 1250 yards (at sea level) and 1000 foot-pounds energy to about 400 yards. Both numbers predict the rifles chambered in 6 ARC would be effective at longer distances.

Hornady designed its loads for AR-15 gas-operated rifles, which limit desired pressure to about 53,000 psi. They also noted that the same loads can be utilized in a bolt gun, max pressure for which was rated at 62,000 psi. In most of a thousand rounds of load development, staying strictly with published loads, we were able to get another 100+ fps from 16- and 18-inch bolt guns, thereby also increasing energy and effective range. That brings performance up to near-243 Winchester levels with less recoil and less muzzle blast. In other words, we think the new 6 ARC cartridge and short, handy barrels make a great combination.

The round is certainly new, but the line up of gun makers chambering for it is significant. Hornady lists these other companies as chambering rifles for the 6 ARC: Adams Arms, APF Armory, Barrett, Brenton, Brownells, CMMG, Geissele, Howa, Lantac, Mile High Shooting Accessories, Mossberg, NEMO, Noveske, Odin Works, Radical Firearms, SanTan Tactical, Seekins Precision, Stag Arms, Uintah, and others. We expect the list will continue to grow.

How We Tested

All testing was done at American Shooting Centers in Houston. We fired multiple five-shot groups at 100 yards using a Caldwell TackDriver Pro rest and a large rear bag from Tab Gear. We obtained three Hornady rounds for the test, 103-grain ELD-X expanding Precision Hunter ammo from Battle Hawk Armory, Hornady Black 105-grain boat-tail hollow points from Able Ammo, and Hornady 108-grain ELD-M Match rounds from MidwayUSA.com. We used well-proven Vortex PST II Viper 3-15×44 scopes ($1000, Amazon.com) on both rifles for accuracy testing. The Vortex Viper has the same EBR-7C reticle we use on the Gen 3 Vortex Razor scope mounted on our match rifle, and we love having the consistent view. The image is clear, crisp, and precise. The 600-yard targets fired at were easy to see and hit. As is our normal practice with Pic rails, we used Warne Maxima rings.

Considering the utility of the lightweight Christensen Scout, we also fired it with a 1-10×28 Crimson Trace Hardline Pro as well as a Trijicon MRO, $460, mated to a Trijicon 3X magnifier, $379, both from OpticsPlanet.com. Here’s how the 6 ARC performed in our test rifles.

Gun Tests Grade: A-

$2100

Christensen Arms is located on the east side of the Wasatch Range in Utah, a bit south of Provo and Salt Lake City. Starting out in the aerospace industry, the company soon discovered that precise engineering and lightweight products also worked well on firearms. Though not as light as the company’s titanium models, the new Scout Rifle chambered in 6 ARC is a prime example of Christensen’s expertise.

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Weight savings start with a 16-inch carbon-fiber-wrapped stainless-steel barrel. The tube is button rifled, hand lapped, and free floated. It also sports a match chamber. The muzzle is threaded 5⁄8×24 for a suppressor or other accessory, and a three-prong flash hider is provided.

The minimalist receiver continues the weight-saving process. Dimensions are kept small where possible. There is even a flat milled on the off side of the receiver to save another ounce or so. The bolt is a bit oversized and then attached to a skeletonized bolt handle. The bolt and even the bolt shroud are fluted to shave off a little more weight. Everything is finished with what has proven to be a very durable black-nitride process. The Christensen Scout uses the same MDT 10-round magazine the Savage does, and we give props to both for their choice. Magazine release happens via a long lever immediately in front of the trigger guard. We found an effective magazine-release technique to be wrapping the fingers of the support hand around the front of the mag while we pushed forward on the release with the thumb.

Then there is the Trigger Tech field trigger. With the flat face we prefer and easily adjusted by the shooter with no disassembly, it closely matched the performance of the factory Savage trigger. Required compression was 1.5 pounds, with a standard deviation across 10 pulls of 2.1 ounces. This was a very consistent piece protected by a trigger guard with lots of room for gloved hands. A 0-minute-of-angle (moa) Picatinny rail comes mounted, though we think the cartridge and rifle are worthy of a 20-moa rail for longer shots. But because the rifle is set up for Remington 700-pattern accessories, finding and changing such parts is simple if you want to do that.

The stock is a carbon-fiber-composite made by Christensen Arms. Our sample was tan with black webbing. Action screws are secured through stainless-steel bedding pillars, and the recoil lug is spot bedded. The profile of the stock is thin, with the bottom of the fore end being rounded. This made it easy to carry in the hand, but not quite as firm on a bag on the bench as with the Savage. A forward mounting rail is provided. This Pic rail makes it easy to mount a bipod, but it doesn’t provide a forward sling-swivel stud. Because we would want to carry this rifle slung for hunting, we decided to add a GG&G aftermarket piece that attached a sling swivel stud to the rail, meaning we could no longer also mount a bipod. One of the few disagreements we had with Christensen on the design of the rifle, we would have preferred to see the same two forward sling swivel studs the Savage had. The buttstock does provide the necessary rear sling-swivel stud just in front of a thin, but soft, recoil pad.

We tested the Christensen Scout with the same Vortex Viper we used for the Savage. We also thought that, given the trim look of the Scout, a smaller optic was called for. First, we tested a close-range setup from Trijicon. We mounted the MRO with a 2.5-moa dot and then added a Trijicon 3x magnifier. This setup allows the shooter to use just the red dot, or quickly pivot the magnifier in place and bring things closer. Using this set up, 100-yard groups were just more than an inch. This would be an outstanding set up for running game or a truck gun.

As well as the Trijicon worked, we thought a LPVO (low powered variable optic) might be just the ticket, so we tested a Crimson Trace 1-10×28 Hardline Pro model on the rifle. We reviewed this scope in detail in the November 2022 issue of Gun Tests, finding that the clear image and a reticle designed for precise hold overs worked well in mid-range application. Once again, we were not disappointed. We found 600-yard hits on 20-by-30-inch plates were easy, but the 8-inch plates we have on that 600-yard range were a bit much for that combination of optics.

Feeding and function were perfect. Accuracy was virtually identical to the Savage, losing only by an average of 0.051 inch per group. Five hundredths of an inch is about as tight as we can replicate the measurements on the caliper, meaning the two rifles were essentially tied. Where the Savage preferred the Hornady 105-grain BTHP Black ammo, the Christensen did not, averaging five-shot groups that measured 1.34 inch. The Hornady 103 ELD-X and 108 ELD-M rounds, on the other hand, averaged 0.789 and 0.888-inch groups, respectively. All said, we were impressed by what we saw in the 6 ARC cartridge.

Our Team Said: We did not discover any magic loads, but we did find two solidly performing rifles and a cartridge that outpunches the 5.56 rounds available now. The Scout had an aggregate accuracy result that came within 0.05 inch of the Savage. We see one of the primary advantages of an intermediate cartridge being chambered in a rifle like the Scout is enjoying the rifle’s light weight — 2 pounds lighter than the Savage — without punishing recoil. Also, if we had to carry the rifles far in the field, we would pick the Scout, even with its much higher price.

6 ARC Range Data

Value Guide: Short-Action Bolt Rifles