September 02, 2019
By Joseph von Benedikt
Photos by Michael Anschuetz
It happens sometimes. It was the last hour of the last day of a mule deer hunt in a very, very good Utah unit, and I hadn’t taken a buck.
My equipment certainly was not at fault. I was hunting with Nosler’s new M48 Mountain Carbon Rifle, which is one of the coolest backcountry rifles to come down the pike in recent years. No, my failure to make meat could be blamed entirely on the hunting gods. Over the years I’ve noticed that in every big hunting camp, there is one hunter who is plagued by lousy luck. Seemingly, it was my turn.
Aggressively managed for mature bucks, this area had already produced fantastic deer for my hosts—John Nosler, Jeff Sipe, and Zach Waterman—and several others in our hunting party. Directed by the full-time biologist who oversaw the area, guides unwaveringly passed bucks of less than 5.5 years age. I almost cried when we let a giant go on the third day—the big buck’s rack was wide, massive, and had extra points off each side—because he was “just” four years old.
Now, as I snicked the safety off, the tilting sun struck gold off the tines of another, older buck feeding 310 yards away. His rack was tighter, but heavy, and with cheaters off both sides. I leaned into the bipod, locked the crosshairs on the shoulder of the buck, and squeezed the trigger, sending a 140-grain 6.5mm AccuBond across the swale speeding along at Mach 2.5.
Lung shot, the buck staggered a few steps and locked up. I never take chances, so I put a second bullet squarely through the heart, tipping the deer over in his tracks.
Designed to feed the growing need for backcountry-capable precision hunting rifles, the Mountain Carbon Rifle proved itself that week. I carried it in badlands-type low desert bluff country, in high alpine country, and in just about every type of terrain between. It’s an excellent combination of desirable features: light enough to pack up mountains (just 6 pounds), accurate enough to make precise shots at extended distances, and possessed of ergonomics that help the hunter access that accuracy from field positions.
Here’s a closer look at the concept, design, and hardware that make the Mountain Carbon Rifle exceptional.
Nosler’s action is well engineered and nicely built, bordering on custom-action quality. The bolt features dual, opposing locking lugs; a stout 0.24-inch-wide extractor; and a robust plunger-type ejector that heaves empty cartridge cases out the ejection port. Long, shallow, straight flutes run the length of the bolt body and provide a place for mud or crud that finds its way into the action to accumulate, enabling it to continue functioning. A teardrop-shaped, knurled bolt knob assists positive grasp even with cold or wet hands. The rear of the bolt is nicely set off with a well-contoured, faceted shroud that mirrors the octagon-shaped receiver top.
A small bolt release is located at the left rear of the action, opposite the two-position, rocker-type safety. The two-position safety does not lock the action when engaged, allowing the chamber to be unloaded with the safety engaged.
The M48 receiver is machined to accept any scope bases designed for the Remington Model 700. As a result, excellent scope mounting options are almost endless.
The bottom metal is aluminum and is reminiscent of the classic Winchester Model 70, featuring a nicely shaped trigger bow, a hinged floorplate secured with a small push-button/latch at the front of the trigger guard, and lovely lines overall. Magazine capacity is three magnum cartridges or four standard cartridges.
For added protection against corrosion, all metal parts are finished with Cerakote, which offers outstanding resistance to abrasion, saltwater, and other potentially harmful corrosive elements.
Traditionally, Nosler uses very good barrels. The combination of very good barrels and careful gunsmithing provides Nosler rifles with an excellent reputation for accuracy. Opting to use a carbon-fiber-wrapped barrel made by Proof Research puts the Mountain Carbon Rifle in another category. Known for excellent accuracy combined with best-in-class rigidity, Proof’s barrels tend to provide performance bordering on that of large-profile match barrels—but in weights comparable to traditional mountain-rifle barrels.
Proof Research builds all of its barrels in-house: cut rifling bores, handlapping, and turning the slender cores to correct profile before wrapping them in space-age carbon fiber impregnated with heat-conductive resin adhesive. Even the fibers are laid on in a fashion engineered to shunt heat from the core down the length of the barrel and to the surface, resulting in a barrel that heats slowly and cools quickly. Importantly, the resin base has an expansion rate similar to that of steel, so core-carbon fiber delamination does not occur.
Over the past several years, Proof Research barrels have vaulted to the top of the category, becoming widely respected as the best-available option for building a mountain-weight rifle with match-grade accuracy. Nosler opted to use one of the slenderest profiles—the Light Sendero—on the Mountain Carbon Rifle. It’s well set to the action, perfectly centered in the free-floated fore-end channel, chambered with studious care, and threaded up front for easy installation of a muzzle brake or a suppressor.
Made entirely of carbon fiber reinforced with Aramid—which is a close cousin to Kevlar—the Mountain Carbon Rifle’s stock is arguably the best-designed stock ever put on a Nosler rifle. It’s lightweight, which is critical to the model’s designation as a mountain rifle, yet extremely rigid, which is vital to consistent, predictable accuracy across a wide spectrum of temperature and in torque-inducing field positions. I confess it’s not my favorite of Nosler’s stocks in terms of looks, but it offers outstanding design features. A subtle palmswell and just-right grip curve position the shooting hand comfortably and in a way unlikely to induce torque. A minimal Monte Carlo on the comb enhances cheek-to-stock position consistency, and a narrow flattish bottom area down the length of the fore-end stabilizes the rifle when it’s rested on anything from a sandbag to a daypack.
As mentioned, the fore-end is free-floated to enable best-possible accuracy. Additionally, actions and bottom metal are pillar and glass bedded into the stock.
Because the Mountain Carbon Rifle is offered in everything from mild-recoiling cartridges, such as the 6mm Creedmoor and the 6.5 Creedmoor that I used, all the way up through heavy-hitters like the 33 Nosler, a premium recoil pad is vital. Nosler chose well and installed a Pachmayr Decelerator.
The rifle I used on my hunt was completed just a week prior to the hunt and was one of the first Mountain Carbon Rifles produced. I received it just a few days before the hunt, so I didn’t have a lot of time to become acquainted with it. However, I found it to be very accurate with the Nosler 140-grain Ballistic Tip factory ammo I had on hand, but that load did not produce the velocity out of the Mountain Carbon Rifle that I think is necessary for a mule deer hunt in mountain country. It averaged just 2,573 fps from the rifle’s 24-inch barrel. So I assembled one batch of a handload consisting of Nosler cases, Nosler 140-grain AccuBond bullets, 41.5 grains of H4350 powder, which is an almost fail-safe powder recipe for excellent accuracy in the 6.5 Creedmoor, and Federal Gold Medal Large Rifle primers.
My handload’s accuracy was good, and velocity averaged 2,730 fps. As I detailed earlier, the load cleanly dropped a very good mature mule deer buck at 310 yards. Informal forensics showed that both bullets performed splendidly, expanding to large diameter and passing completely through the buck.
Hunting partner Jeff Sipe—the brains behind the Mountain Carbon Rifle—got on an outstanding heavy-antlered buck early in the hunt and took it with one shot from his rifle chambered for 26 Nosler.
After I returned home from the hunt, I decided to give the Mountain Carbon Rifle a thorough workout at the shooting range with seven other factory loads. I’ve included the results along with those for my handload and the previously mentioned Nosler factory ammo in the accompanying chart. As I usually do with rifles chambered in 6.5 Creedmoor and fitted with a large-diameter barrel, whether all steel or wrapped in carbon fiber, I fired three consecutive three-shot groups without allowing the barrel to cool. That process enabled me to ascertain whether accuracy would worsen and point of impact would shift as the barrel heats up. I did allow the rifle to cool completely between the testing of the different loads.
Nosler guarantees sub-MOA accuracy with “prescribed Nosler ammunition.” The Mountain Carbon Rifle performed better than that, averaging at or below 1 MOA with seven of the nine loads I tested.
My hot-barrel accuracy test revealed that point of impact shifted upward about a half-MOA as the barrel heated, consistently somewhere between shots five and six. That’s forgivable, as this is a mountain hunting rifle, not a match gun, and if you haven’t gotten the job done with four to six rounds, you have more to worry about than a minimal point-of-impact shift.
Critically, the Mountain Carbon Rifle is a natural from field positions, balancing beautifully and stabilizing nicely. It’s an outstanding backcountry rifle.