Comparison of the .308 Win., .30-06 Springfield., .300 Mag., and .338 Win. Mag.

    [ Written by Dr. Jim and Mary Clary ]

    Yep, this is yet another article on the 30+ caliber cartridges. In this article, we used data obtained from the Nosler Reloading Guide, 5th Edition. To make the comparison as fair as possible, We selected the 180 grain bullet, which is available in each caliber. And, for loads, we chose 2 grains below the maximum recommended for each caliber with IMR 4350. IMR 4350 was chosen since there are loads in all four calibers for that powder, and we want uniformity. You may prefer a different powder to obtain higher velocities or greater accuracy, but for comparison, as many variables as possible must be controlled. Note: We do not be use the solid base BT for most of our shooting, but again to fairly compare the calibers, the bullets had to be the same. Recoil was calculated for 8 lb rifles.

    The calibers compared are the .308 Winchester, 30-06 Government, .300 Winchester Magnum and .338 Winchester Magnum. They represent the most popular calibers in the 30 – 35 caliber range.

    These calibers have accounted for every game animal that walks our continent (providing you follow rule number one: proper shot placement). The .308 Winchester and 30-06 Springfield are very close in ballistics and recoil. The choice is purely personal.

    There are, however, major disagreements over the .300 Winchester Magnum and .338 Winchester Magnum. The difference in recoil of 4 pounds may not seem like much at first, but after you shoot both, you can definitely tell the difference. While the .300 is not a joy to shoot like the .308 or 30-06, it is definitely more comfortable than the .338.

    The muzzle energy of the .338 is impressive, and at first glance, superior to the .300. However, it drops off rapidly, and by the time the bullet reaches 100 yards, the energies are comparable. Add that fact to the heavier recoil and the only argument favoring the .338 magnum is the larger diameter and heavier bullet for dangerous game.

    It is questionable in our minds whether a .338 magnum is needed by many hunters. Animals do not have titanium bones or joints. They are not wearing body armor, and a modern, well-placed 30 caliber bullet will do the job in every instance that we can imagine (unless you are going for Grizzly…. Then we would want a .375 instead of the .338). So, why the argument? Is it because a lot of folks believe the .300 magnum to be as close to the 30-06 as to be a duplicate? The tables above debunk that belief. Is it because folks believe that if they are going to a magnum, why not get “more bang for the buck” and get the .338? If that is their reasoning, why not just get a .375 magnum and call it good?

    We don’t know the answer to those questions. However, we have heard some hunters say that they like the “brush busting” capability of the .338 magnum. Ok, but we prefer not to shoot through brush. We’d rather hold our shot until we have a clear unobstructed view. That is probably why Jim passed on a royal bull elk in the Colorado Rockies 40 years ago. He never could get what he considered was a clear, clean shot… so he passed and the bull lived to see another spring. Jim has never regretted his decision. Between us, we have been hunting for almost 80 years, from PA to Wyoming and never needed anything bigger than a 30 caliber. However, we also have rifles in .223 Rem. and .243 Win. calibers for occasions when a .308 Win., 30-06 Spfd. or .300-338 magnum are too much.

    Ruger Nr. 1: Illustration courtesy of Sturm, Ruger & Co., Inc

    Which of the magnums do we shoot? Easy answer: Jim shoots a Ruger Nr.1 chambered for the .300 Win. Mag. He can load it up or down as the occasion demands and has a wide variety of bullet weights to select from. Mary’s .300 Win. Mag. is a customized Ruger M77 Mk II with a purple-thumbhole stock and muzzle brake. It shoots like a .243 Win. She can drive tacks with her purple gun at 100 yards. Since neither of us plan on hunting for Grizzly anytime in the future, we have decided to pass on buying a .338 Win Mag.

    100 yards with the Mary’s purple Ruger M77 Mk ll (not pictured)

    We won’t resolve the argument over calibers here, but hope that we have provided a little more “fuel for the fire” with our discussion.

    Steve Johnson

    I founded TFB in 2007 and over 10 years worked tirelessly, with the help of my team, to build it up into the largest gun blog online. I retired as Editor in Chief in 2017. During my decade at TFB I was fortunate to work with the most amazing talented writers and genuinely good people!