The 7mm-08 and the 7mm Remington magnum are two extremely popular 7mm cartridges that are often used for similar purposes. Because these two cartridges are used for the same tasks and have the same bullet diameter, it would only make sense to compare the two to see which one is better and why.

Here is the short answer:

When you compare the 7mm-08 and the 7mm magnum with the same bullet weights, the 7mm Magnum has 20 inches of less drop and 5 inches of less wind drift at 500 yards. The 7mm Rem Mag also has 500 more foot-pounds. If you need a heavy-hitting cartridge, you will want the 7mm magnum. But if you are using your rifle for not much besides deer then you will want the 7mm-08.

Now that we have looked at the short answer, we can go more in-depth about the ballistics, history, and different specs of each cartridge to see how they compare to each other.

7mm-08

The 7mm-08 is a direct copy of a wildcat cartridge called the 7mm/308. Around 1958 Remington took this cartridge claimed it as their own and mass-produced it. This cartridge was released by Remington in their model 788, 700, and 7600 rifles as a deer hunting cartridge. 

The 7mm-08 is a cartridge that is used primarily for elk, deer, hog, and antelope hunting and some is sometimes used for long-range shooting. This cartridge has a good amount of power and a flat trajectory leading it to be an ideal caliber for big game hunting at close to medium range (close to medium range being under 350 yards). 

The 7mm-08 gets its name because it is a 308 case necked down to a .284 aka 7mm bullet. By doing this, the 7mm-08 has 200 less foot-pounds and feet per second of velocity at the muzzle, but beyond 300 yards, the 7mm-08 overtakes the 308 in energy, velocity, and has less drop and less wind drift.

At the muzzle, the 7mm-08 has 2400 foot-pounds and 2650 feet per second of velocity with a 150-grain bullet. At 500 yards with a 100-yard zero and a 150-grain bullet, the 7mm-08 has 930-foot pounds of energy, 23 inches of wind drift, and 65 inches of drop. 

7mm Remington Magnum

The 7mm Rem Mag was introduced in 1962  and was marketed to be better than the somewhat successful 264 Winchester Magnum. Eventually, the 264 died off and the 7mm magnum took the place as the most popular caliber in its class.

The 7mm Magnum is very popular among elk and deer hunters, and has even been used to take game as large as moose. This cartridge is often considered one of the best elk hunting cartridges because of its long-range energy and flat trajectory. The 7mm Mag is also very popular among long-range shooters because of its high velocity, low wind drift, and high energy. 

Many different calibers were used to design this one. This round used was based on the 264 Winchester, the 338 Winchester Magnum, and the 300 H&H Magnum. Remington used what they liked most about each of these cartridges, fixed the problems, and made the 7mm Magnum.

At the muzzle, the 7mm Remington Magnum with a 150-grain bullet, has 3300 foot-pounds of energy and 3110 feet per second of velocity. At 500 yards with a 150-grain bullet, the 7mm Rem mag has 1370 foot-pounds of energy, 2000 feet per second, 20 inches of wind drift, and 44 inches of drop with a 200-yard zero. Overall this cartridge is super powerful and has s super flat trajectory.

Which cartridge is better and why

Now that we have looked in depth at each cartridge, we can compare the two to see which cartridge is better for different situations and why. 

If you need a heavy-hitting powerful cartridge, you will want the 7mm Magnum. The 7mm Rem Mag has the ability to hold up to 82 grains of powder while the 7mm-08 can only hold 52 grains of powder. The 7mm Magnum can also use bullets that weigh as much as 195 grains. 

For lighter skinned game, like deer or antelope, the 7mm-08 is the better cartridge. The 7mm Remington Magnum, while it is popular among deer hunters, is overkill for many situations. Unless you are hunting deer or antelope at 400 plus yards, the 7mm Mag will often be overkill. 

Wise of long-range shooting, the 7mm Remington Magnum is the better cartridge. The 7mm magnum has much more energy making it better at reaching out to long-range and not being affected by wind or drop. 

On an overall case comparison, the 7mm Magnum has a 0.491-inch shoulder while the 7mm-08 has a 0.454-inch shoulder, the 7mm mag also has an overall length of 3.29 inches compared to 2.8 inches of the 7mm-08. This seemingly minute difference is the biggest factor in why the 7mm magnum has more energy and more powder capacity than the 7 mm-08. 

If you had to choose one cartridge over the other you would have to choose the 7mm Rem Mag. The 7mm Remington Magnum has a larger array of bullet weights making it more versatile than the 7mm-08.