March 29, 2023
The 7mm Rem. Mag. was introduced in 1962 in the also brand-new Remington Model 700. Both took off rapidly, and other actions quickly adapted to the new cartridge. At least by 1970 it was a standard chambering among manufacturers that had actions housing its 2.5-inch case.
Within a decade it would rise to be the most popular cartridge we call “magnum,” a position it held for a quarter-century. Today that title is held by the .300 Win. Mag. I can’t say when the worm turned, but I have some data.
In 1989, I surveyed all the African professional hunters I could find for my Safari Rifles book. Under recommendations for “medium plains game,” the 7mm Rem. Mag. was second only to the .30-06. In the African context this makes sense, because little long-range shooting is done over there.
In 2007, I did the same survey for Safari Rifles II. This time, the Big Seven fell off the page—single-digit mentions overpowered by huge consensus for the .300 Win. Mag. and .30-06. Even the .270 beat it in both “light” and “medium” plains game categories. The 7mm Rem. Mag. was still popular, ammo made by everyone, so I was surprised at how much it slipped.
In that same period, I got another shock. Kimber introduced its Mountain Ascent, the lightest factory rifle probably ever. The 7mm Rem. Mag. was noticeably missing from early chamberings. The company’s marketing director was a buddy, so I asked why. His answer: “Our dealers don’t want it.”
Maybe that was an anomaly, but the Big Seven isn’t dominant. Fine, we have lots of good cartridges, and the 7mm Rem. Mag. remains an accurate, effective and versatile hunting cartridge. When it was new, Jack O’Connor poo-poohed it by saying it wouldn’t do anything his .270 couldn’t do; earlier he said much the same about the .264 Win Mag.
Because of heavier bullets, Big Seven is more versatile than .270. On larger game, I don’t think it’s more powerful than the ’06, because of frontal area and bullet weight. Certainly, it doesn’t equal the magnum .30s. I’ve done quite a bit of sheep and goat hunting with a 7mm Rem. Mag. while I’ve never taken a .30-06 on a serious mountain hunt. Why? The Big Seven shoots flatter. A fast .30 with heavier bullets of equal aerodynamics shoots as flat but kicks more.
The worst thing I can say about the 7mm Rem. Mag. is that it’s not my cup of tea. We cannot love all cartridges equally, and the 7mm Rem. Mag. never became a favorite. However, it has been the chambering of much-loved rifles, with a long history.
To date I’ve owned four Big Sevens, not a big number, but I’ve used the 7mm Rem. Mag. on all the continents and on all types of game except really big stuff. My first 7mm Rem. Mag. came along in 1979, when the cartridge was at the height of its popularity. That rifle, a Savage 110, was my first left-hand bolt-action. When the wood stock warped on a wet caribou hunt, it also became my first synthetic-stocked rifle.
I don’t know why I never fell in love with the cartridge. Maybe just because everybody was using it. I can say it never let me down. I didn’t do much elk hunting with it, so I rarely used 175-grain bullets. The elk pictured in the lead photograph in this article fell to a single 160-grain bullet; I usually went with medium weights bullets from 160 to 165 grains, pushed to about 3,000 fps. Favorites included 160-grain Partition, 162-grain InterLock, and 165-grain GameKing. The 162-grain 7mm bullet has sectional density of .287. In .30 caliber, you must go clear to 190 grains to equal that section density.
Among the 20-odd million words I’ve written, I’ve made mistakes. The one I regret most was relative to the 7mm Rem. Mag. We don’t know what we don’t know, and not everything is on the Internet.
I came into this business at a wonderful time, when members of the previous greatest generation of gun writers were mostly still around. During the 1950s, pundits were clamoring for a fast 7mm. Americans Phil Sharpe and Richard Hart developed the 7x61 Sharpe & Hart, adopted and chambered by Schultz & Larsen in Denmark in 1953. It got a lot of publicity, but it didn’t catch on. The shorter (2.394 inch) case restricts velocity, but the 7x61 isn’t far behind the 7mm Rem. Mag.
Remington introduced the .280 Rem. in 1957. Based on the .30-06 case, it solved the .270’s bullet weight deficiency and shot flatter than the .30-06. The .280 may be the very best .30-06-based cartridge. Original loads were conservative to ensure functioning in Remington’s semiauto. Initial sales were slow, and the .280 has never been as popular as it deserves. Despite cries for a faster 7mm, legend has it Remington was reluctant to try again.
In the 1950s, P.O. Ackley was one of America’s best-known rifle guys. Ackley wildcatted everything, long since creating his 7mm-06 Improved. Fred Huntington at RCBS took the .280, removed body taper, gave it a 35-degree shoulder, and created the .280 RCBS. Ackley later gave it a sharper 40-degree shoulder to create his .280 Ackley Improved. The timeline is mushy, but the .280 AI—which is experiencing a resurgance today—probably came after the debut of the 7mm Rem Mag.
Here comes my egregious error. Warren Page, shooting editor at Field & Stream, was a staunch fast 7mm guy. He was also a very astute technical guy and a benchrester, and from 1949 on, Page used almost exclusively a 7mm Mashburn Super Mag.—a .300 H&H case with body taper removed. As a result, I have given Page undue credit for the 7mm Rem. Mag.
So if not Page, who was Big Seven’s daddy? Les Bowman was a Wyoming outfitter, rancher, gun writer and rifle authority. I didn’t know him, but Bowman’s friend and neighbor of many years, Ryan Selby, filled me in.
Per Selby, Bowman wanted a fast 7mm, capable of taking elk at long range. He wanted a 160-grain bullet at 3,150 fps, with a goal of obtaining 1,800 ft.-lbs. at 500 yards. He necked down a .338 Win. Mag. case to 7mm.
Fred Huntington made the dies, and Parker Ackley barreled an action, creating the wildcat .280-.338. Remington’s Mike Walker came out to hunt with Bowman, probably fall of 1960, and subsequently Bowman went east to meet with the Remington brass. They called him just two weeks later. No changes to Bowman’s case dimensions. Les Bowman deserves majority credit for the Big Seven.
Acceptance of the 7mm Rem. Mag. was almost immediate. Introduced in 1958, it blew the doors off Winchester’s .264. The 7mm Rem. Mag. didn’t shoot any flatter than the .264, but the added versatility of heavier bullets was obvious.
Part of the Big Seven’s early success was also timing. It was still in diapers when Winchester made its 1964 firearm design changes and consequently lost a lot of fans. The .264 nearly died, and 1963’s .300 Win. Mag. almost didn’t have a chance. It took a long time to surpass the Big Seven.
The 7mm Rem. Mag. was a home run, and largely because of its success the 7mm came to be thought of as a “Remington caliber.” It already had the .280 (for a time called the 7mm Express), and after the 7mm Rem. Mag. it introduced the 7mm-08 Rem. In 1989 Remington adopted Layne Simpson’s 7mm Shooting Times Westerner—a full-length cartridge with awesome velocity. It is over-bore capacity, but its biggest problem was lack of suitable propellants. That has changed with new, slow-burning propellants. The 7mm STW is faster than the 7mm Rem. Mag., but finicky.
Remington did it again in 2000, adding the full-length 7mm Rem. Ultra Mag. Again, faster, but very over-bore capacity. Neither the 7mm STW nor 7mm RUM have been especially popular.
In 2001, Winchester aced Remington with the 7mm WSM, almost duplicating 7mm Rem. Mag. performance in a short, fat short-action case. This created a major problem for Big Green because the WSM case was a bit too long to be housed in its short Model Seven action.
One must wonder how many times you can go back to the well with one bullet diameter, no matter how popular. In 2002 Remington introduced the 7mm and .300 Rem. Short Action Ultra Mag cartridges, which were perfectly sized for the slick little Model Seven.
Both Short Action Ultra Mags are nearly gone, and the 7mm WSM hasn’t fared much better. But how has the 7mm Rem. Mag. come to its current state?
For one, it has a belted case. In 1888 Peter Paul Mauser proved that neither an exposed rim nor a belt were essential for headspacing, and the recent onslaught of fat-cased unbelted magnums have surely proven that a belt doesn’t define magnum performance. While it’s otherwise sound, The Big Seven has a belt, thus it’s an antiquated case design.
The 7mm Rem. Mag. isn’t going away, but I doubt it will see an upsurge in popularity. Its .284-inch bullet remains popular, with wide choice in bullets. Nosler standardized the .280 Ackley Improved in 2006, and while it’s not burning up the world, it is gaining ground. With similar velocity to the Big Seven, yet unbelted, it’s doing better than I expected.
The .28 Nosler is the first of the Nosler cartridges to go beyond proprietary. Based on the Rem. Ultra Mag case, it’s fat, unbelted and shortened to alleviate over-bore capacity, it is catching on. It calls for faster twist barrels to accommodate today’s heavier low-drag bullets, which are increasingly common. The long-standard 1:10 twist of the 7mm Rem. Mag. can’t stabilize them, so you can rebarrel or start over.
Just released is Hornady’s 7mm PRC. Like the other PRCs, it’s based on the .375 Ruger case and shortened to 2.280 inches. It calls for a 180-grain bullet at 2,950 fps, barrel twist specified at 1:8 inches. I’m shooting it in a Mossberg Patriot, the first chambering from a major manufacturer. It’s providing good accuracy, with recoil much the same as the 7mm Rem. Mag.
Because it has a .532-inch rim and base diameter—same as the 7 Rem. Mag.’s rim and belt—any existing 7mm Rem. Mag. can be rebarreled to the 7mm PRC without bolt face modification, and feeding should not be an issue. This should make it especially interesting to Big Seven fans who crave the new extra-heavy bullets.
Every new fast 7mm with modern case design is another nail in the 7mm Rem. Mag.’s coffin, and today’s hunter preference for heavy bullets doesn’t help. But I don’t predict the Big Seven will go away—not after 60 years of popularity.
The Earlier Fast 7mms
Holland & Holland introduced the .275 H&H in 1912. Using a .284-inch bullet, it’s based on the belted .375 H&H case shortened and necked down to 2.5 inches. Its 175-grain factory load was rated at 2,680 fps. Western loaded it in this country before World War II. Per Ryan Selby (see main article), Jack O’Connor gave Les Bowman a .275 H&H, but because of the body taper Bowman couldn’t get the velocity he wanted, so he moved on to the .338 case.
There were several fast European 7mms, starting with the 7x64 Brenneke (1917), which is similar to the .280 Rem. The list includes the 7x73 Vom Hofe, almost alone as a belted European cartridge. Except for the 7x64, none of these achieved great popularity, but they prove that a faster 7mm wasn’t just an American concept.
The weirdest thing about the 7mm Rem. Mag. story is that the fast 7mm performance Americans were looking for already existed. The 7mm Wby. Mag. was one of Roy Weatherby’s initial developments. Like the Big Seven, the 7mm Wby. Mag. is based on the belted H&H cartridge—shortened, with body taper removed. The biggest difference is Weatherby’s signature double-Venturi shoulder, but there is only .001-inch diameter difference at the shoulder.
The Weatherby case is longer than the Remington at 2.549 inches, but it has a longer neck, so it has slightly less powder capacity. However, it consistently outruns the 7mm Rem. Mag. by at least 100 fps because of presseure standards. The 7mm Rem. Mag. is held to 61,000 psi, while the 7mm Wby. Mag. is loaded to 66,000 psi.
While it delivered the performance people were clamoring for long before the Big Seven came along, it was a one-company proprietary. The 7mm Rem. Mag. brought big-company availability and less expensive ammo.