308 Winchester Load Data

The .308 Winchester is about as All-American as you can get in the cartridge world. Like dozens of other cartridges, it came about by modifying the good old .30-06 Springfield. But this apple didn’t fall far from the tree. The .30-06 case was merely shortened by 0.479 inch, and the shoulder angle was changed from 17.5 degrees to 20 degrees. The base and rim diameters are the same, and of course, it’s still a .30-caliber, which has been America’s favorite bullet diameter for generations.

And like the .30-06, the .308 Win. has its roots in the U.S. military. In 1954 the U.S. Army introduced a new cartridge called the 7.62x51mm to replace the .30-06, which dated back to 1906. The astute marketing wizards at Winchester were well aware of the Army’s developments and that military cartridges almost always become popular commercial cartridges. In 1952, two years before the announcement of the Army’s cartridge, Winchester adroitly introduced it as the “new” .308 Winchester. In the ensuing 70 years, the .308 Win. has been a phenomenal success in the big-game fields, on target ranges, and just about everywhere gunpowder is burned. Virtually every maker of centerfire rifles chambers models for the .308 Win. From lightweight mountain rifles to bull-barreled behemoths, the .308 Win. rules the roost, as there are rifles—and even handguns—for every purpose and every shooter.

It is notable that the .308 Win. case has been necked up and down to produce many successful factory cartridges, to say nothing of wildcat cartridges of all shapes and forms. For example, the .243 Winchester and .358 Winchester, .260 Remington and 7mm-08 Remington, and the .338 Federal are all consanguineous derivatives of the .308 Win.

The .308 Win.’s popularity is well deserved; it is a potent and versatile round. Velocities are only a bit slower than the .30-06, due to the round’s slightly smaller case capacity and the rifling twist. The .308 Win. case turned out to be slightly more efficient than the .30-06 and was found to be capable of excellent accuracy with a wide range of bullet weights and types. The .308 Win. has a slightly higher maximum average pressure (MAP) of 62,000 psi; the MAP of the .30-06 is 60,000 psi.

The standard twist for the .308 Win. is one turn in 12 inches, while the .30-06’s twist is 1:10 inches. This makes it more suitable for lighter bullets, but less than optimal for the heaviest big-game bullets. Nevertheless, the .308 Win. has been a bestseller for decades, and it’s a premier hunting round because it is suitable for just about all big game except for the largest critters. When I hunted moose in Finland a few years back, I encountered a fellow hunter who plugged a huge calf moose. I asked him what caliber he used and expected him to say 6.5x55, one of the 9.3mms, or some such. “It was .308,” he happily replied.

Such popularity also means that thousands of shooters load their own .308 Win. ammo. In fact, the latest “Die Popularity List” from RCBS lists .308 Win. dies as the fourth most sold, topped only by the 6.5 Creedmoor, .223 Remington, and 9mm Luger. The terrific selection of bullets, cases, and powders for the .308 Win. provides almost endless combinations for test loads that make reloaders absolutely giddy.

Tips & Techniques

Reloading the .308 Win. offers plenty of satisfaction and few problems—as long as the handloader sticks to the basics and the usual safety protocols for bottleneck cartridges. Although lever guns and semiautomatic AR-type rifles are available, most .308s are bolt actions, so I’ll concentrate on loading techniques for them.

Of course, as with any reloading project, the first and probably most important “tool” the reloader should acquire is one, or more, of the excellent reloading manuals. They are chock-full of information, with plenty of detail for both the beginner and seasoned reloader. For safety’s sake, read them first. They also will save you time and money.

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Case preparation is totally uncomplicated. After cleaning and inspecting cases for splits and defects, the sizing die should be set to barely touch the case shoulder, so as to not set it back much: 0.002 to 0.003 inch is about right. This can be done with the time-honored “try and fit” technique to get that “slight crush fit,” but a headspace gauge works better. (I like Hornady’s Lock-N-Load Headspace Comparator.) Careful adjustment of the sizing die also helps prevent incipient case head separations, too.

Another excellent sizing method when loading for bolt guns is to use a neck-size-only die or use the full-length sizer backed off a bit to size just the neck. As long as the cases will be used in the rifle in which they were fired, neck sizing is a good way to make cases last longer, and many reloaders are convinced it also makes for more accurate reloads.

Case length is important for uniform reloads. The maximum case length for the .308 Win. is 2.015 inches, and it is generally recommended to trim cases 0.010 inch below maximum. A case trimmer is a miniature lathe, and it whittles off the excess brass in a jiffy. Most are hand-powered, but motorized versions are handy for large numbers of cases. After trimming, debur the case mouth with (what else?) a deburring tool. A good dial caliper is handy to have for checking case lengths.

If a case is longer than the chamber (yes, it happens, and there are gauges to measure actual chamber length), the case can be pinched between the bullet and the barrel when the round is fired. This can cause hard chambering, make pressures jump, and does not help accuracy. If the reloader wants to crimp in a bullet’s cannelure, having cases all the same length is pretty much mandatory. In addition, it is not impossible to buckle or bulge a case if crimp force is excessive. In any event, cases that have the same overall length contribute to the round’s uniformity, accuracy, and safety. Case trimming is an important step if the bullet chosen has a cannelure and the reloader wants to crimp the case into it.

The .308 Win. is so well balanced that almost any quality Large Rifle primer is suitable for reloads. However, many reloaders dote on match-grade primers, such as the Federal GM210M and the CCI BR-2 primers. I hate to be a party-pooper, but I have not noticed any appreciable differences in performance with any of the excellent primers available these days.

Just about all reloading presses come with an add-on provision for case priming, but almost no one uses them. Instead, a hand-priming tool is the hands-down favorite. Lyman, RCBS, Hornady, and many others make neat priming tools. They’re easier, faster, and safer, as they keep greasy fingertips off the primers. Make sure the primers are seated flush or a hair below the case head.

What do we do if we come into a big batch of once-fired 7.62x51 military cases with crimped-in primers? Well, of course, there are tools to deal with that, too. First, the primer must be removed. While the decapping stem in your sizing die will probably do this without bending or breaking, why take a chance? Most companies make a decapping-only die. They work for virtually all cases, are extremely stout, and save wear and tear on your sizer. I use a Lee Universal Decapping die for this, and I haven’t found a primer that it can’t defeat. After the case is deprimed, you then have to get rid of the left-over crimp. While there are dies that “swage” out the crimp, I prefer a reamer in a power case-prep unit. Many companies make these, and they save time and fingers.

Also, be wary of “range brass.” The reason it’s lying there may be that it has already been reloaded many times. Such brass is not worth the risk. Pass it up.

One last caveat on priming. Some cases of European origin have Berdan primers. The anvil for them is in the primer pocket, not in the primer itself. Berdan primer pockets have two sneaky little “snake-eye” flash holes offset to either side of the case’s anvil. Yes, they can be reloaded, but it is most certainly not worth the effort. In addition, if you inadvertently let a Berdan-primed case slip into the batch you’re resizing, it will probably break the decapping stem in your die. The best solution for cases with Berdan primers is to toss them in the scrap brass bin for recycling.

Load Selection

First, one must define the role of the intended reload. Is it to be a light plinking load? Is it meant for hunting varmints, deer, or larger game? Or is it for paper punching? Once that’s decided, I recommend selecting three or four bullets that might be suitable for the job.

Probably not a lot of rounds of .308 Win. are expended on varmints, but suitable specialty bullets for these critters are available. The Speer 125-grain TNT HP and 130-grain HP are good choices, as are Hornady’s 110-grain V-Max and 130-grain Spirepoint bullets. Not to be overlooked is the Nosler 110-grain Varmageddon Flat Base Tipped bullet. Similar lightweight bullets are also available from Barnes, Sierra, and Berger.

Deer (and, as I’ve noted, Finnish moose) are on the menu for the .308 Win. Suitable bullets weighing from 150 to 165 grains fill the bill here. Nosler’s AccuBond and Ballistic Tips and Hornady’s SST, GMX, InterLock, and InterBond forms in 150, 155, 165, and 168 grains are proven performers.

Larger game calls for larger bullets, and there is no shortage of them. Tough projectiles of 178 and 180 grains are about perfect. Remember, the .308 Win. has a 1:12-inch twist, so it may not be highly accurate with long, heavyweight bullets in the 190-, 200-, and 208-grain weight range. Plus, the .308’s moderate powder capacity won’t produce enough velocity with heavier bullets to cause reliable expansion. An exception may be a bullet like Hornady’s 220-grain RN, which might stabilize due to its shorter length. As with any cartridge, it never pays to try to turn the .308 Win. into something it isn’t with handloads.

Propellants

An entire book could be written on powders suitable for the .308 Win. It’s a medium-size case, with a middle-of-the road expansion ratio, and the vast array of bullets available make for a versatility that is hard to match. There are many potential powders for each possible use. Thus, this turns into a treasure hunt for the “perfect” bullet and powder combination for the job. Your loading manuals and the online data bases of many bullet and powder companies list plenty of potential propellant choices.

Caution: There are zillions of loads for the .308 Win. from questionable sources out there. View them with a jaundiced eye. Use only pressure-tested data from reliable sources like your loading manuals and trusted online sources like the Hodgdon Reloading Data Center. Just because Joe Blow from Kokomo reports on the internet that he uses “xx” grains of Whozifritz abc powder doesn’t mean that it is even remotely safe.

There used to be a running debate on whether to weigh each powder charge or use a powder measure. That debate has been pretty much settled with the advent of superior drum-type powder measures and lots of powders that meter with great uniformity. Also, it was proven decades ago that slight variations in powder charges have very little effect on velocities. However, a uniform technique in operating the measure is an important factor in accurate reloads.

Of course, you have a scale (manual or electronic) and probably a powder measure. All manuals list a “starting” load, and it is indeed a good place to start. The “maximum” loads are just that. Don’t exceed them! Actually, most of my .308 Win. loads are sorta kinda middle of the road. After all, accuracy comes first, and top accuracy doesn’t always come with the highest velocity.

There is one more important piece of reloading equipment: a small flashlight. After charging the cases, shine the light into each case to see if they all have the same amount of powder in them and that you haven’t missed one. The size of the .308 Win. case won’t hold a double charge, but an “underload” is also dangerous, so checking is an important safety measure.

As for powder suggestions, the potential bullet and powder combinations are almost endless, and the ones shown in the accompanying chart are just a few suggestions. You should try any and all the combinations from reputable data sources that intrigue you. One or more will surely turn out to be winners. However, basically, one could get by with just two or three powders for all the bullets weights in the .308, but where’s the fun in that?

The accompanying Accuracy & Velocity chart relates the results from typical .308 Win. reloads in the bolt-action rifles listed. Each rifle had its favorites, but all four of the test guns were plenty accurate. The test regime was three, five-shot groups fired at 100 yards from a benchrest. Velocities were measured with the chronograph placed 10 feet from the guns’ muzzles. All rifles grouped right around an inch, and the overall group average was a tidy 1.11 inches.

Here are a couple of specific loads from each test rifle as examples of the versatility and accuracy of the great .308 Winchester.

The short-barreled Remington Model Seven averaged 1.17 inches for all nine loads tested. The best of the bunch was the Hornady 178-grain ELD-X over a charge of 44.0 grains of Hodgdon CFE 223 powder. The average velocity was 2,378 fps, for a muzzle energy of 2,236 ft-lbs. The Speer 165-grain Grand Slam and 48.3 grains of VihtaVuori N550 produced 2,415 fps and a 0.94-inch group average. These are two fine game bullets.

My Franchi Momentum rifle is a favorite of mine, and it is a proven game-getter. On a recent safari for exotics in the Texas Hill country, it batted 100 percent, collecting nine animals with nine shots. The five test loads from its 22-inch barrel averaged 0.83 inch. Again, CFE 223 was tops. Nosler’s 165-grain Partition and Ballistic Tip bullets and Speer’s 150-grain Grand Slam all averaged under an inch, as did the Nosler 150-grain AccuBond with VV N550. All are fine big-game loads.

The Winchester XPC rifle was a late addition to the mix, but it performed admirably. It has a 20-inch barrel and averaged 1.08 inches, with seven of its 11 groups averaging an inch or less. A charge of 42.0 grains of IMR 8208 XBR propelled the Hornady 165-grain GMX lead-free bullet to 2,612 fps and averaged accuracy of 0.94 inch. With the Nosler 150-grain AccuBond, 47.5 grains of CFE 223 clocked 2,713 fps and averaged 0.83 inch. And I must mention Federal’s 165-grain Trophy Bonded Tip bullet. Its accuracy and performance on game has been exemplary. Over 49.0 grains of Power Pro 2000-MR, the velocity was 2,677 fps, and groups averaged 0.84 inch.

The last test gun is my ancient Ruger Model 77R. It dates from 1982 and has been a go-to rifle for many years. It still delivers good accuracy, averaging 1.12 inches for the 10 loads tested for this report. The favorites were the Nosler 165-grain Partition over 46.8 grains of CFE 223 (2,701 fps and 0.92 inch), the Speer 165-grain Grand Slam with 45.0 grains of Reloder 15 (2,612 fps and 0.88 inch), and the Nosler 150-grain AccuBond over 46.3 grains of VihtaVuori N540 (2,783 fps and 0.78 inch).

As we peruse the specific loads, a trend sorta pops up. Most of the “favorite” loads listed used 150- or 165-grain bullets; the 178-grain ELD-X is a delightful exception to this. This makes sense, as the .308’s 1:12-inch twist is just perfect for such bullet weights.

Thus, as we evaluate the grand old .308 Winchester, we see that there are many reasons why it is so popular. It is exceptionally accurate, has adequate power for most game, and is just a delight to handload. I’m not going to kid you and say that the .308 is my “favorite” cartridge. However, there has always been at least one .308 Win. in my battery—and always will be, along with dies and a good supply of components.