Winchester launched its .308, the sporting version of the 7.62x51 NATO military round, in 1952. The cartridge offered ballistics that nipped at the .30-06’s heels from a shorter action, and that made the .308 a popular chambering option for bolt-action, semiauto, lever-action and slide-action rifles. Hunters appreciated the cartridge’s mild recoil, low cost, the availability and selection of .308 bullets as well as its effectiveness on game.
The .308 case gave wildcatters fresh clay to sculpt, and within a decade of the .308’s release, somebody came up with the 7mm-.308, a necked-down version of the .308 that held 7mm bullets. In 1980, Remington decided there was consumer demand for a commercial version of the 7mm-.308 wildcat, and the 7mm-08 Rem. was born.
Since the 7mm-08 and .308 share the same parent case with almost identical capacities, this is more a battle of 7mm versus .30 caliber projectiles than it is about case design. The .30 caliber remains the most popular bullet diameter for U.S. hunters, and as such, there are more bullet options.
That gap is thin, though, and the 7mm bullets offer higher sectional densities and ballistic coefficients. They are long and heavy for caliber. A 150-grain 7mm Nosler Partition bullet, for example, has a G1 ballistic coefficient of .456 and a sectional density of .266. A 150-grain .308 Partition, by contrast, has a G1 BC of just .387 and an SD of .226.
Given these two projectiles of the same weight fired at the same velocity, the 7mm bullet will buck wind better, shoot flatter and penetrate deeper. A 7mm-08 load with a maximum charge of IMR 4895 powder will push a 150-grain Partition bullet at 2,750 fps from the muzzle, according to Nosler’s Reloading Guide 8. A max charge of the same powder will push a 150-grain .308 Partition bullet at 2,802 fps.
With this load, the .308 load has 100 more foot-pounds of energy at the muzzle, but at 400 yards the 7mm-08, with its more aerodynamic bullet, actually has almost a 100 ft.-lbs. advantage over the .308 load and shoots half-an-inch flatter at that distance when zeroed at 200 yards. Wind drift for the 7mm-08 load is 2.4 inches less at 400 yards than it is for the .308, too.
Commercial hunting loads for the 7mm-08 have bullets that range up to 160 grains while .308 ammunition tops at about 185 grains, and with bullets from 150 to 160 grains, the 7mm-08 will outperform the .308. The .308 comes closer to 7mm-08 trajectories with heavier bullets, but at the cost of increased recoil over the 7mm cartridge.
This would indicate the 7mm-08 is the better of the two cartridges, but demand for the .308 says otherwise. It draws fans from competitive shooting, hunting and tactical disciplines, and in terms of rifle availability, the .308 is the clear winner, with plenty of semiautos, lever actions and even pumps—plus bolt guns of every flavor, from heavy-barreled tactical guns to lightweight mountain rifles. Yes, there are plenty of new and used 7mm-08s, but the number doesn’t begin to approach the vast array of .308s.
Midway USA currently offers 125 different .308 Win. loads, compared to just 27 7mm-08s. If you stop at the local gas and grocery store to pick up ammo, your odds of finding .308 are better than your chances of finding 7mm-08 ammo. In terms of cost, both of these rounds are similarly priced. You can expect to pay between $1.25 and $1.50 per shot on average.
In truth, these are both great cartridges. It could be argued the .308 is better suited for large game thanks to heavier bullets, but it could also be argued the 7mm-08, with its lighter, faster, flatter-shooting bullets and less recoil, is better for medium game and varmints.