LJ Bonham is a semi-subsistence hunter, hunting magazine editor, and firearms enthusiast who lives in the Rocky Mountains.
What’s the most popular, yet least glamorous, hunting rifle cartridge? The .308 Winchester. Developed for the U.S. military to replace the time-tested .30-06, this wonderful, flexible round traces its DNA back to the .300 Savage.
Based on lessons learned from the German StG-44 and its shortened 7.92mm cartridge, the Army’s Frankford Arsenal wanted something to match the .30-06’s ballistics with lower recoil, and fit into the new, trimmer service rifle in development at the time.
From NATO to You
Winchester debuted the new cartridge in 1952, two years before the U.S. military adopted it as the 7.62mm NATO along with the M-14 rifle. The service load fired a 147 grain full metal jacketed bullet at 2750 feet per second from the M-14’s twenty-two inch barrel with an effective range over 800 meters. The round gained an instant reputation for superb accuracy.
Replaced after less than a decade by the M-16 and its 5.56x45mm round, the M-14 soldiers on today with American snipers and special operations forces, while the 7.62mm NATO is used in medium machine guns such as the M-240. The M-14 and the 7.62x51 provide the long range punch the 5.56x45 lacks, and have proven invaluable for engaging targets across mountain valleys in Afghanistan and elsewhere.
One Cartridge to Rule Them All
The .308 is considered a deer cartridge by many, but with the right bullet, it can take anything from marmots to bears. It is perhaps the most versatile short-action cartridge ever made, and its case has been used for many other short-action rounds such as the .243 Winchester, .260 Remington, 7mm-08, .338 Federal, and .358 Winchester. Bullet weights available for the .308 range from 110 grains to 208 grains, with 150 to 165 the most popular. Bullets heavier than 208 grains are not suited to the .308 due to limited case length.
By the Numbers
From a twenty-four inch barrel, the .308 can fire a 110 grain bullet at over 3300 fps, perfect for varmints and small predators. The most common load, a 150 grain, leaves the muzzle at a nominal 2800 fps, and is used for deer and antelope-sized game. Heavier bullets such as 180 and 200 grains travel at 2600 and 2450 fps, respectively. Either is suited to elk, moose, or black bear. The .308 has another great advantage; most ammunition companies offer low priced, 150-grain FMJ loads, which are great for inexpensive practice, and limit hide damage on fur bearers such as coyote and wolf. With match grade components, the .308 has won trophy after trophy in target shooting competitions.
Loaded with a premium hunting bullet such as the Nosler Partition, Barnes TSX, or Swift Scirocco, the .308 hits harder than mere numbers would suggest. With proper bullet placement, it is not unusual for animals to drop in their tracks when shot with this mid-size round.
Easy on Your Gun
The .308 has another significant advantage: it is a low-overbore cartridge. Overbore is the ratio, expressed as a coefficient, between the barrel's bore area and the cartridge case's powder capacity. The smaller the bore and the larger the case capacity, the higher the overbore coefficient. Overbore is linked to barrel throat and bore erosion or wear. High-overbore cartridges tend to erode barrels at a much faster rate than low overbore ones. For example, the 7mm Remington Magnum which uses a 7mm, or .284 caliber, bullet has an overbore coefficient of 1326 and is notorious for eroding barrels after just a few thousand rounds in some cases. The .308's overbore is 751, almost half the 7mm's. A .308's barrel should last a long time with proper care and cleaning; something to think about if one can't afford to replace rifles or barrels often.
.308 vs. 7.62 NATO Issues
In recent years the .308 has become even more popular as AR-type rifles have taken the civilian firearms market by storm. The original AR-10, which fathered the M-16 and its variants, was chambered for the 7.62mm NATO round, and most AR makers offer a model in .308. While the .308 and 7.62 NATO appear identical, internal and external case dimensions can vary due to military rifle chamber specification. It is important to not use military cases in rifles marked for .308 Winchester. Rifles with NATO spec chambers can use both 7.62x51mm and civilian .308’s as they have more generous headspace and overall chamber size.
Results of using 7.62 NATO cases in .308 rifles
The .308 Winchester: versatile, powerful, efficient, and gentle on shooter’s shoulders. A great, get the job done and go home cartridge which gains new popularity with each hunting season and serves the military with distinction. A true working-class hero.
This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.
© 2016 LJ Bonham
LJ Bonham (author) on August 17, 2018:
Glad you enjoyed my Hub. You raise a valid question, which, on its face, seems reasonable. I can't advise you in this area. You should contact the technical staff at Nosler, Hornady, Hodgdon, or another bullet or power manufacturer. I'm sure they could give you all the info you need.
Howard on August 17, 2018:
Since the case capacities are so different, would it be acceptable to download the NATO brass to account for the lower case capacity due to less room to avoid an over-charge situation?
Obviously, less powder would account for less velocity, one would think, but would the smaller case interior/less powder still allow for comparable velocity because the powder burn/pressure would make up for any shortfall in powder weight/charge?
Thank you for the interesting article.