When someone contacted me recently to suggest this Caliber Battle matchup, I couldn’t believe we hadn’t done it before. If you ask your average American hunter which big boy caliber he uses, the .300 Win. Mag. and the 7mm Rem. Mag. are the two most likely candidates. And the data backs that up: among the product offerings on Midway USA, these are the two most popular magnum rifle cartridges in the country.
The popularity of both cartridges speaks to their efficacy, but if you have to pick one, which is better? That’s the question we seek to answer in the Caliber Battle series, and this matchup is no different.
Ballistics
If you’re choosing to hunt with a magnum rifle cartridge, ballistics is the category you care about most. Magnum aficionados don’t mind a little recoil, and these loads are designed to take everything from antelope to moose to grizzly bears.
Both the .300 and the 7mm will give you what you’re looking for. There are plenty of differences between these cartridges (which we’ll get to in a minute), but they’re also strikingly similar. Most loads top out around 3,000 feet-per-second (fps), and there are plenty of options for both cartridges using bullets in the 150- to 175-grain range.
But we’re not here to declare a tie; we’re here to declare a winner. To compare bullets of similar weights, these 154-grain 7mm Rem. Mag. bullets top out at 3,045 fps, and these 165-grain .300 Win. Mag. loads hit 3,110 fps at the muzzle. For those counting, that means in this particular comparison, the .300 offers about 10% more energy at the muzzle than the 7mm since it pushes a slightly heavier bullet slightly faster.
That edge holds true in other comparisons as well. In the loading data published by Frank C. Barnes in “Cartridges of the World,” the Win. Mag. offers 12% more energy among 150-grain bullets, 17% more energy among 160/165-grain bullets, and 10% more energy among 175/180-grain bullets.
Power isn’t everything when it comes to taking down an animal, but it sure doesn’t hurt. And it makes sense–the .300 Win. Mag. boasts a 10% greater case capacity than the 7mm Rem. Mag., so it can push heavier bullets faster than its counterpart.
Depending on bullet type and construction, increased velocity offers the added benefits of less bullet drop and wind drift. But in this comparison that difference might not be as much as you’d expect. Returning to the example linked above, that 165-grain .300 Win. Mag. has a BC of 0.41, and with a 200-yard zero drops 6.4 inches at 300 yards, 38.1 inches at 500 yards, and 155.4 inches at 800 yards.
The 0.433-BC 154g 7mm Rem. Mag. follows a similar path: at 300 yards it drops 6.6 inches; at 500 yards it drops 39 inches; and at 800 yards it drops 157 inches.
On average, the .300 Win. Mag. offers more power than the 7mm Rem. Mag, and it can be more easily found loaded with heavy, high-BC bullets. That’s why it gets the nod in this category. But as the examples above suggest, you’re unlikely to notice a huge difference in the field.
Winner: .300 Win. Mag.
Shootability
This category measures how easy each cartridge is to shoot–both in terms of the force on your shoulder and the gravity-like force of ammunition on the dollar bills in your wallet.
You’ll spend at least $1.50 per round on .300 Win. Mag., and quality hunting rounds will run between $2.50 and $3.50 per round. The 7mm Rem. Mag. costs almost exactly the same.
But while both cartridges come with similar costs, the 7mm might be slightly more difficult to find. That’s not saying much since every sporting goods store from Maine to New Mexico stocks a few boxes of .300 Win. Mag. Still, if you’re looking for something specific, you might have more trouble tracking down a box of 7mm Rem. Mag. than .300 Win Mag.
Neither cartridge is particularly comfortable to shoot, though I’m not telling you anything you don’t already know. But according to published recoil data and my own personal experience, your shoulder will hurt more after shooting a .300 Win. Mag. than a 7mm Rem. Mag.
Chuck Hawks reports that with an 8.5-pound rifle, a 150-grain .300 Win. Mag. produces about 24 ft.-lbs. of recoil energy while a 7mm Rem. Mag. hits with about 19 ft.-lbs. using the same rifle and bullet weight.
That’s not hugely significant, but it’s enough to notice, especially after a full day at the range. I think that slight edge in the recoil department is more important than the .300 Win. Mag.’s smaller advantage in the ammo availability department.
Winner: 7mm Rem. Mag.
Versatility
The previous two categories have been close calls, and this one is even closer. The 7mm Rem. Mag. is more commonly loaded with lighter bullets in the 140-grain range, while the .300 Win. Mag. is often found with heavy 180-, 190- and 200+-grain offerings. To put it another way, the most common bullet weight for the .300 Win. Mag. is 180 grains, while the most common bullet for the 7mm Rem. Mag. is 150 grains.
That suggests that the .300 Win. Mag. is better suited for larger animals, and there are many hunters who would agree. Certainly, its greater power, velocity, and bullet diameter make a quick, clean kill more likely.
But, once again, I’m not sure how much hunters will notice that difference in the field. And I’m not the only one. Frank Barnes points out that a handloader could make the 7mm Rem. Mag. do “just about anything” and claims it has “ample power for any North American big game and most thin-skinned African varieties.” He’s right. Hunters and competitive shooters have had great success pushing 180-grain Berger bullets from a 7mm Rem. Mag., which negates some of the Win. Mag.’s heavy bullet advantage.
At the same time, Barnes also argues that the .300 Win. Mag. is a “fine long-range, big game cartridge” and is “suitable for any North American species.”
If both cartridges will kill a moose or a grizzly bear just as dead as an antelope or a whitetail, can we really say one is more versatile than the other? Maybe. It’s also worth noting that from the factory, the .300 Win. Mag. offers a wider bullet weight range (about 70 grains from 150 to 220) than the 7mm Rem. Mag. (about 40 grains from 140 to 180).
I’d say that advantage earns the .300 Win. Mag. the slight nod in this category. That being said, if you have a 7mm Rem. Mag., don’t feel like you have to go out and buy a .300 just to go after bigger game.
Winner: .300 Win. Mag.
And the Winner Is…
The .300 Win. Mag. wins this Big Boy Caliber Battle. It offers more power, is more widely available, and can be found factory-loaded with a wider range of bullets. But the 7mm Rem. Mag. isn’t far behind. It also offers magnum power that lets hunters take down large-bodied animals at long distances. If recoil isn’t a big factor for you, either cartridge is worth a look.
Overall Winner: .300 Win. Mag.
