600 Overkill


Need has nothing to do with it”

The name says it all, but there’s a lot more to this cartridge than just a flashy name. From Africa to Alaska, AHR’s 600 OK rifles have taken the most-dangerous game in the most-demanding circumstances.  The 600 OK has been tested, and hunted with, and shot in competitions for over ten years. It has killed Cape Buffalo, Elephant, Hippo, and the biggest Bears. Let me tell you a little more about this awesome cartridge.

The cartridge

The 600 Overkill cartridge was designed by Dr. Rob Garnick, and was a result of his quest for something that would out-perform the 600 Nitro and would also work in a bolt-action rifle. The case is his own original design; it was not re-worked from a 600 Nitro Express or any other case. The belted, straight-wall case is 3″ in length, and has a rim diameter of .635″, the same as the 505 Gibbs. Our brass, made by Jamison International, is of the highest quality and we keep cases in stock at all times to go with new rifles.

458 Lott                       600 OK

The 600 OK is a medium pressure cartridge, with chamber pressures in the high 40k to mid 50k psi. It is also very versatile, with bullet weights ranging from 600 grains to 1,000 grains, and velocities from 1,400 fps to 2,250 fps. The “standard” load, with which most guys hunt, is a 900 grain soft or solid at 2,150 fps. That’s over 9,200 ft/lbs. of muzzle energy. Bump the velocity to 2,250 fps, which is easy to do, and you have over 10,000 ft/lbs. of muzzle energy!!!  Typical powders for the 600 have a  medium burning rate:  H-4350 and Vhitavouri N-550 work well with a 900 gr. bullet. Any Magnum large-rifle primer will work, but we prefer Federal 215’s. There are several sources for good bullets. Woodleigh makes their 900 gr. soft-nose and FMJ, which are available from on-line retailers such as Midway-USA. Other makers are Hawk Bullets, Alaska Bullet Works, Cutting Edge Bullets, and many smaller makers. We have built an extensive database of loads for the 600, and we always have plenty of cases in stock to go with your new rifle, along with reloading dies.

The Rifle 

After the initial development, AHR was the first to offer rifles chambered in the 600 Overkill. Working closely with Dr.Garnick, we designed a rifle built on the extremely strong CZ magnum action. This action is the perfect size for the 600 OK and handles the rounds with ease. AHR then designed rifle components to make the 600 function even better; a vertical stack magazine box and follower, and our efficient “X-Brake” muzzle brake. AHR continues to make improvements to the 600 to make it the best looking and best shooting ultra big-bore that you can own. The 600 OK is a beautiful rifle also. We use the same fancy English Walnut and superb craftsmanship as we do on all of our rifles. You can also order this rifle built on the Granite Mountain Arms action. Just because it’s big, doesn’t mean it has to be ugly.


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