This article will examine the entire .308 family of cartridges as typically factory loaded to SAAMI specifications. The .308 Winchester set the standard for short action rifle cartridges and it is the most successful such design ever created. It was designed by Winchester at the request of the US Army to fire a 150 grain bullet at the same muzzle velocity (MV) as the then standard .30-06 service round.

Due to the great popularity of short action, magazine rifles designed to handle ".308 length" cartridges, the .308 parent case has been necked up and down (usually without other changes) and standardized by the major ammunition manufacturers to accommodate bullets ranging from .243" to .358".

The first cartridge in the family, the .308 Winchester, was introduced in 1952 and the most recent, the .338 Federal, was introduced in 2006. That time span, in itself, is testimony to the astonishing versatility and popularity of the parent case.

The basic .308 case has proven to be so versatile it is fair to say, given appropriate caliber and load selection, that this family of cartridges can properly be used to hunt all North American Game, from varmints to moose. This includes all Class 2 and Class 3 game worldwide at reasonable ranges.

There are many other fine cartridges, but unless dangerous (Class 4) game is on the menu, there is really no necessity for the 21st Century hunter to look beyond the .308 family. (For additional details about the various cartridges included in this comparison, see the Rifle Cartridges page.)

In order to keep this comparison to a manageable size, one standard factory load was selected to represent each caliber. All of these loads use spitzer (pointed) bullets and were chosen to keep this comparison as fair as possible. The representative loads chosen to represent each caliber are:

• .243 - Remington Express 100 grain Core-Lokt PSP bullet (normal bullet weight range 70-105 grains)
• .260 - Remington Express 140 grain Core-Lokt PSP bullet (normal bullet weight range 90-160 grains)
• 7mm-08 - Remington Express 140 grain Core-Lokt PSP bullet (normal bullet weight range 100-175 grains)
• .308 - Remington Express 150 grain Core-Lokt PSP bullet (normal bullet weight range 110-180 grains)
• .338 - Federal Fusion 200 grain Fusion bullet (normal bullet weight range 180-225 grains)
• .358 - Winchester Super-X 200 grain Silvertip bullet (normal bullet weight range 180-250 grains)

The Comparison

We will compare these six cartridges and loads in sectional density (SD), bullet cross-sectional area, velocity, kinetic energy, trajectory, killing power and recoil. At the end, I will conclude with a few pertinent comments and observations.

Sectional Density

The sectional density (SD) of bullets is calculated by dividing a bullet's weight (in pounds) by the square of its diameter (in inches). Note that the shape, material or ballistic coefficient of the bullet has no bearing on SD, only weight and diameter count. If you compare bullets of the same weight in different calibers, the smaller caliber will have superior SD for any given weight.

Sectional density is important, because given bullets of identical design at identical velocity, the bullet with the greatest SD will penetrate the deepest. A simple example is that a long and slender shape like a needle penetrates better than a blunt shape such as a round ball of the same weight at the same velocity.

The deeper the wound channel (of any given diameter) in a game animal the more tissue is destroyed and the greater the killing power. Here are the SD numbers for our selected bullet weights:

• .243 Rem, 100 grain = .242
• .260 Rem, 140 grain = .287
• 7mm-08, 140 grain = .248
• .308 Win, 150 grain = .226
• .338 Fed, 200 grain = .250
• .358 Win, 200 grain = .223

SD's above about .205 are considered appropriate for Class 2 class game (deer, antelope, goats, sheep and black bear). Our chosen bullets in all calibers thus easily qualify for hunting Class 2 game.

The real standout in SD among our calibers is the .260 Remington. This illustrates why 6.5mm cartridges have earned such an outstanding reputation in game fields around the world for deep penetration.

Cross-sectional Area

Bullet cross-sectional area is important, because the wider the wound cavity (of any given depth), the more tissue is destroyed and the greater the killing power. Bullet cross-sectional area is independent of bullet weight.

The actual bullet diameters of our various calibers are .243", .264", .284", .308", .338" and .358". Here are the bullet cross-sectional areas for our calibers:

• .243" = .0464 square inches
• .264" = .0547 square inches
• .284" = .0633 square inches
• .308" = .0745 square inches
• .338" = .0897 square inches
• .358" = .1007 square inches

The .358 bullet will, given the same percentage of bullet expansion, always punch a larger diameter hole than any of the smaller calibers. The advantage in cross-sectional area, not surprisingly, belongs to the two medium bores, the .338 Federal and .358 Winchester, with our four small bore calibers trailing behind.

In terms of the volume of a wound cavity, sectional density and cross-sectional area tend to balance out. Other things being equal, a load that scores well in both categories, such as the .338 Federal, can be expected to create a devastating (wide and deep) wound.

Velocity

Above some certain impact velocity there may or may not be a "shock" effect on an animal's system (that theory is widely debated), but for sure higher velocity flattens trajectory. Velocity is also a major factor in computing kinetic energy. Here are the claimed velocity figures (in feet-per-second) at the muzzle, 100, 200, and 300 yards for our selected factory loads:

• .243 Win, 100 grain - 2960 MV, 2697 at 100 yards, 2449 at 200 yards, 2215 at 300 yards
• .260 Rem, 140 grain - 2750 MV, 2544 at 100 yards, 2347 at 200 yards, 2158 at 300 yards
• 7mm-08, 140 grain - 2860 MV, 2625 at 100 yards, 2402 at 200 yards, 2189 at 300 yards
• .308 Win, 150 grain - 2820 MV, 2533 at 100 yards, 2263 at 200 yards, 2009 at 300 yards
• .338 Fed, 200 grain - 2660 MV, 2450 at 100 yards, 2250 at 200 yards, 2060 at 300 yards
• .358 Win, 200 grain - 2490 MV, 2171 at 100 yards, 1876 at 200 yards, 1610 at 300 yards

The velocity champion of the family is the .243 Win. The .243 starts fastest and ends fastest, but its 300 fps advantage over the .338 Federal at the muzzle has shrunk to 155 fps at 300 yards. This is not inconsequential, but it is less than most of us might have thought.

Except for the .358 Winchester, all the rest of our cartridges show surprisingly similar velocities at 300 yards. We will see how the differences in velocity affect trajectory shortly.

Kinetic Energy

Energy delivered on target, bullet diameter and bullet penetration are the keys to killing power. The bullet's remaining energy at impact powers penetration and expansion. Kinetic energy is essentially a function of mass and the square of velocity and is expressed in foot-pounds (ft. lbs.).

• .243 Win, 100 grain - �1945 ME, 1615 at 100 yards, 1332 at 200 yards, 1089 at 300 yards
• .260 Rem, 140 grain - 2351 ME, 2011 at 100 yards, 1712 at 200 yards, 1448 at 300 yards
• 7mm-08, 140 grain - 2542 ME, 2142 at 100 yards, 1793 at 200 yards, 1490 at 300 yards
• .308 Win, 150 grain - 2648 ME, 2137 at 100 yards, 1705 at 200 yards, 1344 at 300 yards
• .338 Fed, 200 grain - 3140 ME, 2665 at 100 yards, 2245 at 200 yards, 1875 at 300 yards
• .358 Win, 200 grain - 2753 ME, 2093 at 100 yards, 1563 at 200 yards, 1151 at 300 yards

In this important category the relatively heavy bullet and good velocity of the .338 Federal pays dividends. The .338 yields higher energy at all ranges than any of the other members of the family.

The surprise of the clan is probably the 7mm-08. With our selected load, the 7mm-08 has surpassed all of the other cartridges by 100 yards and maintains its edge in kinetic energy all the way to 300 yards and beyond.

Trajectory

Trajectory is important, because a bullet that shoots flatter is easier to place accurately as the range increases. Bullet placement is, by far, the most important factor in killing power.

The following trajectory figures are predicated on scoped rifles with the line of sight 1.5" above the center of the bore. For comparison purposes, each load is zeroed at 200 yards.

• .243 Win, 100 grain C-L PSP - -1.5" at muzzle, +1.6" at 100 yards, 0 at 200 yards, -7.5" at 300 yards
• .260 Rem, 140 grain C_L PSP - -1.5" at muzzle, +1.9" at 100 yards, 0 at 200 yards, -8.3" at 300 yards
• 7mm-08, 140 grain C-L PSP- -1.5" at muzzle, +1.8" at 100 yards, 0 at 200 yards, -7.8" at 300 yards
• .308 Win, 150 grain C-L PSP- -1.5" at muzzle, +2.0" at 100 yards, 0 at 200 yards, -8.8" at 300 yards
• .338 Fed, 200 grain Fusion - -1.5" at muzzle, +2.2" at 100 yards, 0 at 200 yards, -9.1" at 300 yards
• .358 Win, 200 grain Silvertip- -1.5" at muzzle, +3.0" at 100 yards, 0 at 200 yards, -12.9" at 300 yards

The .243 Winchester, due primarily to its higher velocity, has the flattest trajectory across the board. Notice, however, that the second place 7mm-08 stays within +/- 0.3" throughout, an excellent performance with a 40 grain heavier bullet fired from the same size case.

Killing Power

Optimum Game Weight (OGW) is a system devised by Edward A. Matunas to express the killing power of rifle cartridges in terms of distance and the weight of the animal. We need not go into the formula itself here, suffice to say that while not perfect, the OGW system does seem to have a higher correlation with reality than most other systems for estimating killing power. The figures below represent animal weight in pounds and distance in yards.

• .243 Win, 100 grain - 389 lbs. at Muzzle, 294 lbs. at 100 yards, 220 lbs. at 200 yards, 163 lbs. at 300 yards
• .260 Rem, 140 grain - 611 lbs. at Muzzle, 485 lbs. at 100 yards, 382 lbs. at 200 yards, 299 lbs. at 300 yards
• 7mm-08, 140 grain - 688 lbs. at Muzzle, 532 lbs. at 100 yards, 407 lbs. at 200 yards, 308 lbs. at 300 yards
• .308 Win, 150 grain - 757 lbs. at Muzzle, 549 lbs. at 100 yards, 391 lbs. at 200 yards, 274 lbs. at 300 yards
• .338 Fed, 200 grain - 1129 lbs. at Muzzle, 889 lbs. at 100 yards, 695 lbs. at 200 yards, 537 lbs. at 300 yards
• .358 Win, 200 grain - 926 lbs. at Muzzle, 614 lbs. at 100 yards, 396 lbs. at 200 yards, 250 lbs. at 300 yards

The .338 Federal has the advantage in theoretical killing power over all of the other .308 based cartridges. Out to 200 yards, the .358 Winchester stays in second place. Medium bore cartridges are designed for killing large animals, so this is not surprising.

While not represented here, bullets weighing 220 to 250 grains are popular with reloaders who use their .358 rifles on large game. For similar purposes, bullets in the 210-225 grain range find favor among .338 Federal handloaders.

Among the small bore cartridges, the flat shooting .243 Winchester trails the pack at all ranges. The .308 Winchester has the edge at short range with our representative 150 grain factory load and it should be noted that by switching to a 180 grain bullet the .308 shooter can increase the OGW of the cartridge by about 100 pounds at all ranges. By the time the bullets reach 200 yards our selected loads for the .260, 7mm-08 and .308 are quite similar in OGW killing power.

Recoil

Recoil, or "kick," is more important than most hunters realize. Everyone shoots better with a gun that kicks less. That has been proven repeatedly and bullet placement is the most important factor in achieving a quick, humane kill.

Get almost any reasonably appropriate bullet into the vitals and you are in business. A solid hit in the heart/lung area of a Roosevelt elk with a 140 grain .260 bullet is preferable to putting a 270 grain .375 Magnum bullet too far back.

Power will not make up for incorrect bullet placement and flinching due to anticipating the recoil and muzzle blast is the single biggest cause of bad bullet placement. Here are the approximate recoil energy (in foot-pounds) and recoil velocity (in feet-per-second) figures for our representative loads fired in an eight pound rifle:

• .243 Win, 100 grain at 2960 fps - 9.1 ft. lbs. / 8.6 fps
• .260 Rem, 140 grain at 2750 fps - 12.7 ft. lbs. / 10.1 fps
• 7mm-08, 140 grain at 2860 fps - 13.9 ft. lbs. / 10.6 fps
• .308 Win, 150 grain at 2820 fps - 14.6 ft. lbs. / 10.8 fps
• .338 Fed, 200 grain at 2660 fps - 20.8 ft. lbs. / 12.9 fps
• .358 Win, 200 grain at 2490 fps - 18.9 ft. lbs. / 12.3 fps

There are big differences in the recoil of these calibers. The flat shooting .243 can be enjoyed by almost all shooters and its low recoil allows hunters to take advantage of the excellent accuracy delivered by most .243 rifles. The result is precise bullet placement. This is the foundation of the .243's reputation as a fine deer and general Class 2 game slayer.

Among our middle tier of calibers, the .260 kicks noticeably less than the 7mm-08, which in turn kicks noticeably less than the .308. However, all three are within the maximum 15 ft. lbs. of recoil energy with which most shooters can do good work. Balance the factors discussed above against the kick to choose between them.

Remember that these recoil figures are quoted in an eight pound (medium weight) rifle. Reduce the rifle weight to 6.5 or 7 pounds and the recoil figures increase dramatically. The .308 Winchester can go over 20 ft. lbs. of recoil energy and the .338 Federal and .358 Winchester are decidedly unpleasant to shoot with full power loads in an ultra-light rifle.

Reloaders have a definite advantage in this area. A 200 grain bullet at a MV of approximately 2400 fps will still kill decisively out to 200 yards, yet substantially reduces the recoil of a .338 or .358.

Conclusion

It is hard to go wrong with any of the .308 family of cartridges if they are used appropriately. For a combination varmint, small predator and Class 2 game rifle, the .243 Winchester is the obvious choice. Ditto for anyone seeking light recoil and/or extreme accuracy. It is probably the best cartridge available for a first hunting rifle.

For general purpose Class 2 game hunting it is very hard to beat either the .260 Remington or 7mm-08 Remington. Both are superb performers.

The .308 Winchester remains the best choice for mixed bag (Class 2 and Class 3) big game hunts. For big game hunting, it is commonly loaded with bullets weighing 150, 165 and 180 grains. These heavier bullet choices give the .308 an advantage on large game.

For the Roosevelt elk hunter in the dense woods of the Pacific Northwest the .358 Winchester is an excellent choice. The Rocky Mountain elk hunter in more open country would probably favor the .338 Federal. These two are the smallest, high intensity, medium bore cartridges on the market today; the biggest punch available in a small package.