338-06: An ideal North American BIG Game Cartridge!

Written 12/21/98
Updated 3-29-02

The 338-06 is a wildcat cartridge consisting of a 30-06 case necked up to 338 caliber. The 338-06 is quite similar to the domesticated 35 Whelen with power and on-game performance that falls between the 30-06 and 338 Winchester Mag.

The 30-06 is on the light end when it comes to capable Elk cartridges especially at longer ranges as can be demonstrated if you look at most ballistics charts and use the common benchmark of 2000 ft/lb of energy. I question if there are many 30-06 loads that can do this at 200-300 yards with heavy premium bullet. A heavy bullet contains the sectional density necessary to promote deep penetration and bone breaking performance for a tough critter like an Elk or Moose.

The reason I like the 338-06 simply that it has the best combination of attributes for what I want to do with it. The 338 bore can shoot bullets from 200 to 275 gr. with enough energy to be effective on all of North Americas Big Game without being more powerful than is really required. This level of performance creates an ideal North American big game cartridge with less recoil than the 338 Win Mag with significantly more on-game performance than the 30-06.

The biggest difference between the 35 Whelen and 338-06 is the diameter of the bullets, which has a greater impact then it would seem when taken at face value. The 338 caliber is unique, like 6.5mm and 7mm bullets in that these bullets have exceptionally high sectional densities and ballistic coefficients. The reason for these cartridges having this feature is due to the powerful 264 Winchester Mag, various 7mm Mags, and the 338 caliber magnum cartridges such as the 338 Winchester and 340 Weatherby Magnum. These cartridges with their high velocities and traditional use on large game has resulted in bullet manufactures producing heavy, well-constructed bullets designed to perform well with these cartridges.

Bullets in the 338 caliber are available from 180 to 300-gr. weights. The ballistics and energy levels obtained with the 338-06 make it an ideal Elk and Moose caliber to ranges approaching 400 yards, which is as further than I feel is responsible for any Elk or Moose hunter to shoot. With the 250 gr. to 300 gr. bullets, the 338-06 produces around 3600 ft/lbs. of bear stomping power at the muzzle using bullets that are strongly constructed and capable of breaking bone to stop an angry charging bear at close range.

In addition, 338 bullets have a higher sectional densities and higher ballistic coefficients then the 35 Whelen. In addition, the nature of the cartridges themselves results in the 338-06 having a slightly higher velocity (same bullet weight) with a better shoulder for proper headspacing. These traits allow the 338-06 to outshine the 35 Whelen at ranges over 200 yards. In addition, given the popularity of the other 338 caliber cartridges, a better selection of premium bullets is available for the 338-caliber then the 358-caliber. This results in the 338-06 being everything the 35 Whelen is with a slightly better long-range aptitude with a wider variety of premium big game bullets!

The 358 caliber cartridges, such as the 35 Whelen, have never gained the popularity of the 338 caliber cartridges. In as much, the quality and variety of bullets for this caliber is pale in comparison to the 338. Accordingly, the 338-06 is in my opinion what the 35 Whelen should have been as the 35 Whelen and the 338-06 are near equals up to 200 yards or so, and the 338-06 has an advantage from that distance on. The 35 Whelen is a popular Elk cartridge, which provides support for the 338-06 as a cartridge in this same niche.

The 338-06 and 35 Whelen are rounds with considerable recoil (more than 30-06) but this recoil is different than the sharp sock that is received using the high-velocity magnum rounds. The 338 Mags (Win or Weatherby) are fine cartridges, but they deliver substantial energy levels that just arenít needed. These cartridges have a reputation to really sock a shooter when using 225 or 250-gr. bullets. The 338-06 and 35 Whelen, on the other hand, seem to give you a slower push-type recoil (like a 375 H&H) making the felt recoil more manageable. This difference is hard to conceptualize but I think the Mags punch you while the non-Mags tend to push.

To compare the 338-06 to the 338 Win Mag is unwise, as the magnum is clearly a more powerful cartridge. My question is do you need the extra power the 338 Win Mag offers over the 338-06? Personally, I donít as the 338-06 is capable of producing over 2000 ft/lb at 300 yards using a 225 gr. bullet and more than 3000 ft/lb. at close range for big bears.

I have heard people suggested that this same performance could be obtained by loading down a 338 Win Mag. It has been my experience, that loading a cartridge to a lower velocity often results in a lower charge density (how full the case is) which often results in accuracy that is less than desirable. To have top accuracy, it is normally important to have the case as full as possible while maintain proper pressure levels. I am not that familiar with loading a 338 Win Mag, but I doubt it is possible to download is and maintain a full case. With this assumption, I am willing to bet that a 338 Mag with light loads wouldnít be as accurate as a 338-06 of identical performance.

The 338-06 doesnít have the capability of a 338 Winchester Mag nor the 300 Win Mag for that matter, but it is a real world cartridge with enough energy and ballistic capability combined with a milder recoil, common brass (30-06), and a standard length action combine to make this an ideal cartridge for North American big game.

The real drawback of the 338-06 is from the lack of commercially available ammo. With a big game rifle that would be used for hunts where a person would travel, the risk that something could go wrong with a gun, scope, or even not having ammo arive with luggage are causes for concern. This is not a concern with a 30-06, 300 Mag. or 338 Mag as ammo can be bought almost anywhere. It is a shame as this drawback keeps people from buying a 338-06 rifle and until more people buy 338-06 rifles, ammo manufactures and gun shops will not supply the ammo that is needed.

Quarterbore's Postscript:
May 29, 2002

I wrote the above in December 1998 and the information contained in this article remain the same. There have been a few factory rifles made in 338-06 since I originally wrote this and there is limited availability of factory ammo. As for myself, I ended up finding an excellent deal on a Remington 700 BDL SS in 300 Winchester Mag. Given the availability of 300 Win Mag and the fact that I live on the east coast means that I will need to travel to hunt the bigger big game led me to go with the traditional 300 Win Mag over the 338-06. Perhaps one-day factory rifles and ammo will be available and I may finally own my own 338-06 but for now my trusty 300 Winchester Magnum fills this niche in my gun collection and I use to hunt everything from varmints to bear.

Go to Online articles page

Please send your comments, suggestions, contributions or
anything else to: Webmaster@Quarterbore.com.