By now, many of you are aware that Hornady and Sturm, Ruger recently introduced another new cartridge–the .375 Ruger. Chambered in Ruger’s new Hawkeye bolt action, the design objective was to match or exceed the proven performance of the venerable .375 H&H Magnum but in a standard .30-06-length action. Although it is intended for hunting dangerous game, such as Alaskan brown bear and African Cape buffalo, the new round’s moniker curiously omits the signature term “magnum.” Also missing is the ubiquitous belted case typically associated with this type of cartridge.
British armsmaker Holland & Holland designed the first belted cartridge more than a century ago. The .375 H&H Magnum (introduced in 1912) was one of the original loadings having this distinct feature, which, until recently, was synonymous with magnum-rifle performance. Over the years, the .375 H&H has gained the enviable and well-deserved reputation for reliably dispatching animals that can bite back.
Western Cartridge Co. began loading .375 H&H ammo in 1925–a decade before Winchester’s Model 70 became the first domestic rifle chambered for the cartridge. Most of the myriad commercial belted magnum and wildcat cartridges subsequently developed for American sportsmen were based on the .375 H&H and its 30-caliber sibling, the .300 H&H Magnum.
Roy Weatherby got things rolling during World War II by extensively modifying the .300 H&H into the 7mm Weatherby. He quickly followed with similar .257-, .270-, .30-, and .375-caliber rounds. These hard-hitting Weatherby Magnum cartridges became the cornerstone of his very successful company.
Soon, P. O. Ackley and others jumped in and necked the H&H cases up and down, shortened, and improved them into dozens of other wildcat rifle loadings. Weatherby upped the ante a few years later with a new .375-caliber loading based on a belted and reformed version of the even larger .416 Rigby case. The .378 Weatherby Magnum delivered approximately 15 percent more punch than the earlier .375 Weatherby cartridge.
During the mid to late 1950s, Winchester issued a trio of new short magnum cartridges: the .458 Winchester Magnum “African,” the .338 Winchester Magnum “Alaskan,” and the .264 Winchester Magnum “Westerner.” Common traits included a belted case and an overall cartridge length compatible with a standard long action. The intent was to deliver maximum performance in a nonmagnum-length action. Not to be outdone, Weatherby reclaimed top billing with the .460 and .340 Magnums.
In the early 1960s, Remington and Winchester introduced two standard long-action short magnums–the 7mm Remington Magnum and the .300 Winchester Magnum. Remington followed up a couple of years later with two short-action magnums–.350 and 6.5mm Remington Magnums. Of all of these early short and even shorter commercial magnum rifle loadings, only the 7mm Remington Magnum and the .300, .338, and .458 Winchester Magnums have achieved general acceptance. The rest are already or fast becoming also-rans on any current popular cartridge list.
All was quiet for about 15 years until Remington introduced the 8mm Remington Magnum. Simply a necked-down and improved .375 H&H, its claim to fame was that it was later wildcatted into the 7mm Shooting Times Westerner that eventually became a factory loading. The .416 Remington Magnum and, shortly thereafter, the even-hotter .416 Weatherby Magnum ended the renewed magnum cartridge competition for a while. Every one of these has a belted case.
Unless you’ve been asleep for the past few years, you’ve surely heard about Remington’s Ultra Mag and Short Action Ultra Mag, and Winchester’s Short and Super Short Magnum cartridges. A common feature of these recent magnum-rifle cartridges is that their cases are not belted. They are all loosely based on reworking the .404 Jeffery case. Apparently, the H&H design legacy has been interrupted.
I’ve spent some time tracing the history of belted and beltless magnum cartridges because they have continued to play an important role in the development and evolution of new firearms and munitions. Bear with me just a little longer and read about an obscure arms and cartridge designer who–at about the same time that the .375 H&H debuted–designed a cartridge with the most distinct features of the new .375 Ruger.
A century ago, Charles Newton was first recognized when he developed a couple of high-performance cartridges for Savage. The .22 Hi-Power and .250 Savage were the first to achieve the magical 3000 fps performance level. Both loadings were popular then, and they are still chambered in a few European and American rifles. Newton recognized that he could achieve even greater performance by necking the .30-06 case down to launch lighter bullets at maximum velocities. The .256 Newton was actually the precursor of the .25-, 6.5-, and .270-caliber adaptations of the .30-06. Newton soon started his own rifle company, and he went on to design additional cartridges.
After the success of the .256 round, he developed a larger-capacity .30-caliber rimless cartridge. The .30 Newton’s rim/case head diameter was essentially the same as the .375 H&H, but Newton’s was beltless. His new cartridge had the same overall length as the .30-06, so it readily fit the standard long-action magazine.
Later, Newton necked up his .30-caliber creation to form the .35 Newton case. Some references list phenomenal yet somewhat questionable ballistics–.250-grain bullets at more than
2900 fps. Unfortunately, he tried to introduce his new rifle and cartridges at a most inopportune time. The world was engulfed in World War I. And to add to his misfortune, DuPont’s improved military rifle (IMR) propellants, which would have ensured outstanding performance from his overbore rounds, didn’t come along until several years later.
However, the 1948 supplement to Phil Sharpe’s Complete Guide to Handloading relates an interesting story. In the late 1930s, handloader Vernor Gipson necked up the .35 Newton case to .375 caliber and chambered a custom Enfield rifle for his wildcat. Sharpe stated, “With any .375 bullets and 4350 powder, this .375 Gipson-Newton appears to be equal to, if not better than, the .375 H&H.”
Enter The .375 Ruger
The first Hornady/Ruger joint rifle and cartridge venture, the .204 Ruger, debuted nearly three years ago. The first nonwildcat .20-caliber centerfire, it quickly achieved resounding acceptance from varmint and target shooters. Soon, almost all armsmakers added this chambering to their product lines. However, the Hornady/Ruger team’s expectation of success for the new big-bore cartridge is likely more subdued.
When a new cartridge is introduced, the question “Why?” naturally follows. In this case, Ruger needed an alternative choice to its excellent but expensive Mark II Magnum rifle, chambered in .375 H&H and .416 Rigby, to compete in this market. The new .375 Ruger Hawkeye African rifle indicates they believe they have a better product to offer today’s sportsmen. As you can see in the charts, it fully achieves the design objective to meet or exceed the belted .375 Holland & Holland’s performance specs.
The Hornady/Ruger team faces formidable competition in a niche market already well served by the .375 H&H, .378 Weatherby, and .375 Remington Ultra Mag. However, the .375 Ruger cartridge/rifle package is soundly postured, both technically and historically, to successfully meet the challenge.
Handloading The .375 Ruger
When I first saw the new .375 Ruger cartridge, I assumed Hornady achieved its exemplary ballistic performance via heavy magnum propellant chemistry and loading techniques. Therefore, I assumed it was impossible to reload it to factory performance levels.
|RUGER’S NEW HAWKEYE RIFLE|
|The .375 Ruger rifle I used for this report was the African model of Ruger’s new Hawkeye bolt-action rifle. It’s a very traditional rifle, featuring a cut-checkered American walnut stock and matte-blue chrome-moly barreled action. The bolt is matte-finished stainless steel. The steel floorplate is tastefully embellished with the Ruger eagle logo. The new Hawkeye Alaskan model is less traditional, in that it comes with a black Hogue rubber overmolded stock and 20-inch barrel.
Ruger Hawkeye African With Trijicon 3-9X AccuPoint (To enlarge this image, please click HERE
The African’s 23-inch barrel is fitted with rugged express sights. The rear V-notch blade is solidly attached to a windage-adjustable base. Its bold white vertical bar is readily aligned with a prominent white bead that’s set in the front-sight blade. They are regulated for a 50-yard zero. In a recent conversation, Ruger Engineer Todd Wilkinson pointed out that the Hawkeye’s fixed sights are much closer to the bore centerline, as compared to a higher mounted scope, so the difference in point of impact at 100 yards is minimal. Of course, the integral scope-base receiver and supplied rings will accommodate most optical sights. I fired three rounds at both 50 and 100 yards without the scope mounted on the rifle, and the vertical difference in point of impact was just about an inch–just as Wilkinson indicated.
I have an early prototype of the original Mark II Magnum bolt action chambered in .416 Rigby, so I could compare it to the review rifle. The first thing you notice is the new Hawkeye model weighs at least two pounds less. The Magnum’s multiple-leaf rear sight is mounted on a stout quarter rib integral with the barrel. The capability to select a different rear-sight blade could be nebulous in the unpredictable and potentially chaotic situation one might expect when hunting dangerous game.
The Hawkeye model is the third generation in Ruger’s bolt-action rifle lineage, which dates back to 1967. Its stock retains the classic shape prescribed by Lenard Brownell for the original Model 77. Two features of the Hawkeye model that remind me of the original Model 77 include the trimly contoured forearm that hugs the oversized barrel and the red rubber recoil pad. The pad is more resilient than ever, but even it can’t actually tame the .375 Ruger’s severe recoil.
Another feature of the new Hawkeye rifle deserves special attention, too. When the Mark II version of the Model 77 was introduced nearly 20 years ago, one of the least visible but most noted changes was the trigger. While the original Model 77 had a fully adjustable trigger, the Mark II trigger was purposely redesigned so that it was not adjustable. Gunsmithing to smooth it up and reduce trigger pull was an iffy proposition at best. I own several Mark IIs, and the trigger qualities–pull weight, creep, and overtravel–range from pretty good to pretty lousy. The new Hawkeye features Ruger’s improved LC6 trigger that promises to provide consistently better performance.
Albeit belatedly, Ruger had actually recognized customers’ dissatisfaction with the Mark II’s trigger, and the engineers were directed to correct the situation. Wilkinson explained, “We reduced the trigger mass and changed the sear engagement angles slightly to lighten the trigger pull to an average of 4 to 4.25 pounds.”
I thought about that a moment and replied, “You mean you lightened the trigger in order to lighten the trigger, right?”
Wilkinson chuckled and responded, “Exactly!”The external rear surface of the LC6 trigger is slotted to help reduce its overall mass. This distinctive feature readily differentiates the new trigger from the Mark II design. It’s still not adjustable, but I’ve handled several recent production rifles, and their triggers were pretty good.
As you can see in the accompanying charts, the .375 Ruger Hawkeye African model delivered on its performance objectives. This was my first opportunity to shoot a lightweight, large-caliber, dangerous-game rifle. I fired 120 rounds of factory ammo and handloads–most from the bench–in two extended sessions at the range. The .375 Ruger’s ballistics proved to be on par with the proven performance of the .375 H&H Magnum.
Another chart notes the typical recoil energy generated by the .375 magnum rifles fitted with approximately 1.25 pounds of optics and mounts. Recoil is markedly greater when shooting 300-grain factory ammo without the scope and mounts. As you can see, the .375 Ruger will hammer you about like the .375 H&H does in a comparable rifle. The Remington Ultra Mag and Weatherby loads are in a class of their own–that is, recoil runs from 20 to 50 percent higher. In comparison, an 8.25-pound .30-06 rifle (with scope) firing a 180-grain bullet (over a 58-grain powder charge) at 2700 fps generates 21 ft-lbs of recoil.
Shooting any of these rifles is not the most pleasant thing you can do on a nice afternoon at the range. But this cartridge was not designed for that; it was created for hunting dangerous game. Loaded with 270- or 250-grain bullets at up to almost 3000 fps, the .375 Ruger would be a fine round for hunting Africa, and it would be great for elk and big bears. Actually, I suspect it’s in for a serious battle to approach parity with the .375 H&H’s popularity, but not because it lacks in performance!
Let the competition begin.
“Not so,” exclaimed Hornady’s Steve Johnson when I discussed the new round with him. “The .375 Ruger actually has about six percent more case capacity than the .375 H&H. So it should be easy enough to meet or beat that round’s performance with several propellants available to handloaders.”
“Do you have loading data?” I asked.
“Not just yet,” he replied. “We’re still finalizing the factory ammo specs for the 300-grain FMJ loading. We have reloading dies, and of course, the .375 Ruger fits the same No. 5 shellholder as the belted magnums. I’ll put together a package of ammo, brass, dies, and some bullets and ship them out next week.”
While I waited for the shipment, I pulled out my trusty Powley slide rule to compute which and how much propellant to load with 270-grain bullets. Unlike the more recent PC-based programs like Quick Load or Load-From-A-Disk, you don’t need case dimensions to use Powley load, velocity, and pressure calculators. It was designed to predict which IMR powder was suitable to generate 50,000 CUP/PSI–back when copper units of pressure were considered essentially equivalent to pounds per square inch; but that’s another story.
The .375 H&H case holds about 85 grains of water (to the base of the case neck). That means the .375 Ruger case capacity is about five grains more. I set the Powley at 90 grains of water to determine the estimated powder-charge weight, which was 77 grains. So, the charge to bullet weight ratio for a 270-grain bullet is 0.285. I aligned that with the sectional density of 0.275 to figure out which powder to use, and the Powley scale pointed to the “D” powder. That means between 4320 and 4350. According to the instructions, I should add five percent to the indicated charge weight and load 81 grains of the slower-burn-rate powder, IMR-4350, with a 270-grain bullet.
When I reset the charge weight to revise the charge-to-bullet-weight ratio, it was 0.3. The length of the barrel was 21 inches to the base of the bullet, so I aligned that number with the .375-caliber index, and the expansion ratio read between 7 and 7.5. I flipped the Powley computer over, set the charge-to-bullet-weight ratio to 0.3, and the velocity read 2625 fps on the expansion ratio scale.
Comparing that data with what the new IMR Data Center website recommends for the .375 H&H reveals 78.5 grains of IMR-4350 as a compressed charge with the 270-grain Remington bullet to yield 2710 fps at 53,000 CUP. Hornady’s 7th edition manual shows a maximum load of 76.3 grains with the 300-grain FMJ bullet. Because the .375 Ruger’s case capacity exceeds the H&H by six percent, I decided to start with 78 grains under the 270-grainer and work up carefully.
Fortunately, I spoke with Mitch Mittelstaedt at Hornady before I began loading. I commented that the .375 Ruger’s increased case capacity would allow starting with higher .375 H&H load data.
“Whoa, Lane,” Mittelstaedt cautioned. “That’s not so. I had the same idea at first, but when I tested several handloads, chamber pressures ran nearer to max than I anticipated. Apparently, the .375 Ruger’s shorter powder column improves the round’s ignition efficiency enough to shift the burn rate a bit faster. I actually measured the same or a little higher velocities with slightly less charge weights than comparable .375 H&H loads.”
I took his advice and started with lower- end .375 H&H load data. The accompanying chart shows my results with Ruger’s African Hawkeye rifle. Of course, my handloads have not been officially pressure-tested, so if you choose to try them, start five percent below the listed charge weights to be safe.
Will the .375 Ruger be another outstanding cartridge success story? At this point, I don’t know. What I do know is that the round really packs a wallop–at both ends of the rifle.