Compared: The .30-06 Springfield and .338 Federal
By Chuck Hawks
The .30-06 is so well known that it almost doesn't need an introduction. Introduced by the U.S. military in 1906 on the .30-03 case with a slightly shortened neck and a 150 grain spitzer bullet, it quickly became one of the world's greatest all-around hunting cartridges, suitable for all CXP2 (deer size) and CXP3 (elk size) game. With recoil energy of about 20 ft. lbs., it is as powerful as most hunters can learn to handle. (Newbies should one day graduate to a .30-06, not start with it.)
Being a standard .30 caliber cartridge with a bore diameter of .300" and a .308" bullet diameter, there is a huge range of bullets available in both factory loads and to reloaders, ranging from about 100 to 220 grains. However, like most hunting cartridges, there are two or three popular bullet weights. In the case of the .30-06, these are 150 grains (SD.226), 165 grains (SD .248) and 180 grains (SD .271). The 150 grain bullet is best for deer and antelope, the 180 grain is most suitable for large game and 165 grain is the compromise bullet weight. The .30-06 is a standard length cartridge (COL 3.34") requiring a full length rifle action. The industry (SAAMI) maximum average pressure (MAP) for the .30-06 Springfield is 60,000 piezo psi.
The .338 Federal is a 21st Century cartridge, introduced in 2006. It is the first cartridge to bear the Federal name. Numerous articles in the shooting press, including those published by Guns and Shooting Online about .338 wildcat cartridges such as the .338 O'Connor, created a buzz among readers that finally reached the major ammunition companies. A-Square and Weatherby responded first with the .338-06 A-Square in 1998, then Federal introduced the .338 Federal and most recently Hornady and Marlin reacted by creating the .338 Marlin Express.
The .338 Federal has a .330" bore and uses standard .338" bullets, the same as the .338 Win. Mag. There are plenty of .338 bullets on the market, most ranging from 180 to 250 grains. The long 225 and 250 grain bullets take up a lot of space in the short .338 Federal case, so Federal and Fusion factory loads come with 180, 185, 200 and 210 grain bullets. The 200 and 210 grain bullets are probably best for hunting CXP2 and CXP3 game with the same load. The .338 Federal's SAAMI MAP is 62,000 piezo psi.
The .30-06 is the most popular big game hunting cartridge in the world and the .338 Federal is just starting out. Any comparison of the two would be remiss if it didn't point out the vast difference in the availability of rifles and factory loaded ammunition. All rifle manufacturers with an action long enough to accommodate it chamber for the .30-06 and all major ammunition companies offer factory loaded cartridges. Conversely, only ATK's Federal/Fusion, among the major ammunition manufacturers, loads .338 Federal cartridges and only a few rifle manufacturers chamber for the cartridge, at least for now.
For the purposes of this comparison, we are going to stick with representative factory loads. Federal/Fusion, alone of the majors, offers factory loads for both cartridges, so we will use their ballistics. Federal offers the 180 Nosler Partition spitzer bullet (BC .474) in .30-06 factory loads and the similar 210 grain Nosler Partition spitzer bullet (BC .400) in .338 Federal factory loads. Because these bullets are very similar in form and capability, suitable for both CXP2 and CXP3 game, these are the factory loads we will use for comparison. Incidentally, the ballistics of both cartridges are derived in 24" test barrels. We will compare these factory loads in velocity, kinetic energy, trajectory, sectional density (SD), cross-sectional area, killing power and recoil.
Velocity is the most important factor in the equation used to compute energy. It also decreases bullet flight time and hence reduces wind drift and flattens trajectory. Some hunters feel that high velocity per se contributes to killing power, but that has been difficult to prove scientifically. Here are the velocities from the muzzle (MV) to 300 yards in feet per second for our selected loads.
The .30-06 starts out with a 70 fps velocity advantage at the muzzle and finishes with a 150 fps advantage at 300 yards. Clearly, it is the faster cartridge.
Kinetic energy is the measure of a bullet's ability to do work. The "work" in this case is expanding and penetrating deep into a game animal to destroy the maximum amount of tissue and kill quickly. Energy is an important factor in cartridge performance and killing power and a good indicator of the power of similar rifle cartridges. Here are the energy figures in foot pounds for our comparison loads from the muzzle (ME) to 300 yards.
Since about 800 ft. lbs. on target with a suitable bullet is the accepted standard for humanely harvesting CXP2 game and 1200 ft. lbs. is a reasonable minimum for CXP3 game, it is clear that both cartridges have plenty of power. However, the .338's heavier bullet gives it the advantage in kinetic energy within 200 yards. At 300 yards, which as we shall see is well beyond the MPBR of both cartridges, the .30-06 has almost caught up with the .338 Federal in kinetic energy. This is due to the higher ballistic coefficient (BC) of its 180 grain bullet.
The flatter a bullet shoots the less the shooter needs to compensate for bullet drop and the better his or her shot placement is liable to be. The following trajectories (in inches) are computed for the maximum point blank range of each cartridge/load (+/- 3") and assume an optical sight mounted 1.5" over bore and standard atmospheric conditions. Bullet rise and fall in relation to the line of sight are given from 100 to 300 yards.
The .30-06 and .338 Federal are what I would call medium range cartridges. The .30-06 has a MPBR of 269 yards when zeroed at 228 yards. The .338 Federal has a MPBR of 258 yards when zeroed at 219 yards. Both can take deer and similar size game with a dead-on hold beyond 200 yards without fear of overshooting at intermediate distances, but the .30-06 wins the trajectory comparison.
Sectional density is defined as the ratio of a bullet's weight in pounds to the square of its diameter in inches. SD is important because the greater the SD, other factors being equal, the deeper a bullet's penetration. Penetration is an important factor in the length of the wound channel and the amount of tissue disrupted. Obviously, to kill quickly a bullet must have sufficient penetration to reach and disrupt the animal's vital organs. Here are the SD numbers for our .308" and .338" bullets.
Both are well above the .225 SD considered excellent for CXP2 game and are adequate for CXP3 game. The .308/180 grain bullet is superior to the .338/210 grain bullet in this important specification. However, in the field their performance is in the same general class.
Greater cross-sectional area means that, other factors (such as the percentage of bullet expansion) being equal, the fatter bullet should create a wider wound cavity, damaging more tissue and hastening the animal's collapse. Here are the cross-sectional areas of our two bullets in square inches.
As a true medium bore caliber, not surprisingly, the .338 Federal has a meaningful advantage over the .30-06 in bullet cross-sectional area.
There are various ways to estimate killing power, all of which are approximations and none of which are entirely accurate. Bullet placement is the most important factor in a cartridge's effectiveness on game and it is a function of the shooter's skill and judgment, not the cartridge itself. The construction and performance of the bullet is also very important, which is one of the reasons why we have chosen to compare bullets of the same design (Nosler Partition).
An attempt to include at least some of the factors relevant to killing power (primarily impact velocity and bullet weight) is the Optimum Game Weight (OGW) formula developed by Edward A. Matunas and published in the Lyman 47th Reloading Manual. Matunas assumed that bullet design and placement are adequate for the task at hand. The numbers below indicate the size of animal (live weight in pounds) for which each load is presumably optimum at ranges from the muzzle to 300 yards. (For more on OGW, see the "Expanded Optimum Game Weight Table" on the Tables, Charts, and Lists Page.)
Rocky Mountain bull elk average about 500 pounds in live weight. Thus, both of these cartridges are adequate for such animals at distances beyond their MPBR. However, the .338 Federal has an OGW advantage from the muzzle to beyond 300 yards. Its larger diameter, heavier bullet at medium velocity reaps benefits in killing power.
Recoil is always an important consideration, as anyone can shoot better with a cartridge that kicks less. Remember that bullet placement is the most important factor in killing power. Presumably, one of the reasons for choosing either of these cartridges over, say, a .300 or .338 magnum is to minimize recoil. (Sad to say, the .300 and .338 magnums are beyond the recoil tolerance of most shooters, who will develop a game-wounding flinch if they persist in using them.) Here are the approximate recoil energy (in ft. lbs.) and recoil velocity (in fps) figures for our comparison loads, measured in 8.0 pound hunting rifles.
If about 20 ft. lbs. is the upper limit of what most hunters can endure in terms of recoil energy, the .30-06/180 is right there and the .338 Federal is over the top. 2.0 ft. lbs may not sound like much, but it makes a very noticeable difference to most shooters.
Deserving mention in a discussion of recoil is the availability of reduced recoil .30-06 factory loads. Remington offers a Managed Recoil .30-06 load using a 125 grain Core-Lokt PSP bullet at a MV of 2660 fps. ATK's Fusion brand offers a Fusion Lite .30-06 load using a 170 grain .30-30 bullet at a MV of 2000 fps. These loads claim to cut the kick in half (about 10 ft. lbs.) while maintaining adequate killing power for CXP2 game out to 200 yards.
As this is written there is no reduced recoil factory load for the .338 Federal, but there should be! Reloaders, of course, can create their own reduced recoil loads. A 200 grain bullet at about 2200 fps would be a good place to start. Using 36.5 grains of IMR 3031 powder and a Nosler 200 grain Ballistic Tip bullet for a MV of 2191 fps (Nosler figures), the recoil should be about 13.5 ft. lbs. and 10.4 fps in an eight pound rifle.
Summary and Conclusion
The .30-06 Springfield is the most popular and widely distributed of all big game hunting cartridges, far ahead of the .338 Federal in this important area. (Outside of North America, the .338 Federal is practically unknown, so it is not the best choice for hunting overseas.) It also kicks less than the .338 Federal and wins the ballistic comparison in velocity, trajectory and sectional density.
The .338 Federal beats the .30-06 in energy, bullet cross-sectional area and killing power. Both are fine medium range, all-around, big game hunting cartridges. The animals normally hunted, anticipated conditions and the individual shooter's recoil tolerance are key considerations when choosing between these two cartridges.
Copyright 2012 by Chuck Hawks. All rights reserved.