The 7mm Might Be The Ideal Hunting Caliber

In the beginning it was the 7x57mm Mauser and it was good. After we faced it in Cuba—and the Brits faced it in South Africa—it became a world-standard sporting cartridge. It still is, and happens to be my all-time favorite whitetail cartridge. The thing is, it is not fast and falls into a medium-range cartridge. Likewise, its modern ballistic twin, the 7mm-08.

The 7x57 did two things for the gun industry. First, it established that a 7mm uses .284-inch diameter projectiles. Make the conversion: 7mm equals .276-inch; .284-inch equals 7.21mm. No idea why Peter Paul Mauser chose .284-inch and called it “7mm.” Canada’s .280 Ross used .287-inch; other British and metric “7mms” used various diameters. The 7x57’s popularity ensured that modern 7mms all use .284-inch bullets.

Second, the 7x57 was designed around a heavy-for-caliber 173-grain bullet, so it started with a fast-twist barrel, 1:220mm (8.66 inches). This meant it could stabilize fast 140-grain bullets and deep-penetrating 175-grainers, giving the 7mm its marvelous versatility.

It was soon obvious that a 7mm would be better in larger cases at higher velocity. The 1906 .280 Ross was fast. So was Holland & Holland’s .275 Belted Magnum (1912), using the .375 H&H case shortened to 2.5 inches. Almost identical to the 7mm Rem. Mag. introduced 50 years later. Pre-WWI bullet technology hadn’t caught up with speed. The Ross and .275 H&H faded away.

The Speed Evolution of the 7mm

In the 1950s, gun writers Les Bowman and Warren Page clamored for a fast American 7mm. Truth is, they already had one. The 7mm Weatherby Magnum was on the market in 1945, an improved version of the .275 H&H. It was oddly ignored (and still is) but exceeds the 7mm Rem. Mag. Designed by Americans Phil Sharpe and Richard Hart, the 7x61 S&H answered the mail, but it was only chambered by Denmark’s Schultz & Larsen. Though widely touted in gun magazines, it didn’t catch on. I’ve never even seen a 7x61 rifle.

Remington tried in 1957 with their .280 Rem. The most versatile cartridge on the .30-06 case, it was introduced in Remington’s semiauto and initial loads were mild. It never became popular, and is sort of a cult cartridge today. I’ve had several flings with the .280, and notables including Jim Carmichel and Steve Hornady love their .280s.

In 1962, based on Les Bowman’s wildcat, Remington hit paydirt. The 7mm Rem. Mag. became the world’s most popular magnum. Remington’s Big Seven was and is a marvelous cartridge. For at least 15 years, in the 1980s and ‘90s, I did most of my hunting with a gorgeous 7mm Rem. Mag. by the late David Miller. It never let me down, never changed zero, shot well and hit hard.

The Rem. Mag. isn’t as popular as it was then. There are now too many fast, new 7s to choose from. Short cartridges like the 7mm WSM and 7mm SAUM, which almost equal 7mm Rem. Mag. performance. Larger cartridges that exceed it include the 7mm STW, 7mm RUM, 28 Nosler and the latest addition, the 7mm PRC from Hornady.

My son-in-law, Brad Jannenga, does his mountain hunting with a 7mm WSM that he loves, but neither of the short 7mms are chambered in current factory rifles, and ammo is hard to find. With faster 7mms, you run into over bore capacity, too much burning powder to get through that little hole. Over bore capacity is not a showstopper, but it does reduce barrel life.

The Field Narrowed

Disagreement is invited, but this is my story. If you want the versatility of a fast 7mm for Western game in big country, deer to sheep to elk, my advice comes down to four choices: .280 Ackley Improved, 28 Nosler, 7mm Rem Mag, and 7mm PRC. Hardly the only good 7’s, but these days we must consider availability.

.280 Ackley Improved (AI): Possibly the best of P.O. Ackley’s cartridges, the .280 AI is the only one to make it into factory form, now loaded by Federal, Hornady and Nosler. It’s slightly slower than the 7mm Rem. Mag. but offers more compact ammo and increased magazine capacity at little trade-off in performance. It also carries the Ackley advantage. Ackley’s rule for his improved cartridges included the ability for the parent cartridge to be safely chambered and fired. .280 AI is currently more available, but .280 Rem. can be fired in an AI chamber with, in my experience, little loss of velocity or accuracy. My good friend, Lee Newton, does all of his hunting, including whitetail, mule deer and elk with a .280 AI. My Ruger No 1. in .280 AI is one of the more accurate No. 1s I’ve owned.

28 Nosler: Nosler’s family of 26, 27, 28, 30, and 33 Nosler cartridges are all based on the 7mm RUM (.404 Jeffery) case shortened to be housed in a .30-06-length action. So far, the 28 (introduced in 2015), is the most popular, and the only one loaded by multiple firms. It can push a 175-grain bullet beyond 3,100 fps. This comes at a price. Although not disastrously so, it is over bore capacity. Still, for sheer long-range performance on game, the 28 Nosler is hard to beat.

7mm Remington Magnum: Still the availability champion. The 7mm Rem. Mag. may not be the top dog it once was, but it is available everywhere and loaded by everyone. Standard velocities include 160-grain bullets at 2,950 fps and 175-grain bullets at 2,860 fps. This makes it faster and flatter-shooting than a .30-06 with 180-grain bullets. As 7mm fans argue, it has the advantage of higher sectional density, thus deeper penetration, than .30-caliber bullets of similar weight.

7mm Precision Rifle Cartridge (PRC): Introduced in 2022, Hornady’s 7 PRC is the new kid in 7mm town. Propelling the heavy 175-grain ELD-X bullet at 2,950 fps, it is not as fast as the 28 Nosler. Rather, it was engineered for maximum efficiency and barrel life, and to allow the longest and heaviest 7mm bullets in a standard-length action. So far, the 7 PRC is taking off. Federal and others now load it, and rifle platforms are increasing rapidly. It allows greater bullet weight than is possible with the 6.5 PRC, with less recoil than the .300 PRC with heavy for caliber bullets.

So Which One?

If sheer availability is priority, I’d stick with the 7mm Rem. Mag. It’s been a great hunting cartridge for 60 years and nothing changes that. If I were starting over, I’d look hard at the 7 PRC. In fact, I have. I bought a Mossberg Patriot when the 7 PRC first came out, and I’ve just ordered a 7 PRC from Charlie Barnes’s Flat Creek Precision Rifles.

Here’s why: Heavier bullets and rifling twist rates. Bullets up to 175 grains have always been available in 7mm, but most of us who hunt with 7s have used lighter bullets at 140 to 165 grains. That’s fine, but to even the odds against .30-calibers on larger game, I want heavier bullets. As many of us increase our range envelope, we want heavy bullets that are also long and super-aerodynamic. Traditional 7mm twists have been too slow. The 7mm Wby. Mag. and .280 Rem. use 1:10 twists. The .280 AI is specified at 1:9, and Remington used 1:9.25 in the 7mm Rem. Mag.

Stabilization is a matter of bullet length as much as weight. Rifles vary, but any of these twists might stabilize traditional round-nose or semi-spitzer 175-grain bullets. Accuracy is unlikely with longer modern “low-drag” bullets of 175 grains, and now up to 180 grains and more.

New cartridges, including the 28 Nosler and 7 PRC, call for fast-twist barrels. The 28 Nosler specifies 1:9 twist. Seven years later, as the long-range movement advanced and low-drag bullets got longer and heavier, the 7 PRC calls for a very fast 1:8 twist. Nothing precludes building a rifle with faster-twist barrel. Or just rebarreling, but not all of us want to alter existing rifles.

Large Sample Size

In the past 40 years, I’ve hunted with almost all the fast 7mm cartridges. I’ve never used them on pachyderms (or big bears), so I rarely used 175-grain bullets. Recently, I have been incredibly impressed by the effect on game with today’s low-drag 175 and 180-grain 7mm bullets (which will not stabilize in older 7mm barrels). That’s why I’m moving to the 7 PRC: Not to increase range; I’m not an extreme-range shooter on game. Rather, to use heavier bullets to hunt elk-sized game with confidence. Let’s be honest: At similar velocities, a 7mm with 180-grain bullets will produce the same recoil as a .300 Mag. with 180-grain bullets. No savings there, although less than a .300 Mag. with modern 225-grain low-drag bullets. So, if neither longer ranges nor performance on larger game is of interest, this is a silly discussion. Stick with the good old 7mm Rem. Mag. and be happy.

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