Whether Seyfried’s Nyati, the Wells or GMA Express, the word most often associated with .585 is big.

The world would be a smaller and sadder place without 200-mile-an-hour Ferraris, Dobermans trained to go for the crotch, black Cuban cigars, bluewater sailing craft and 585-caliber rifles. If history is any indication, and it almost always is, we don’t have to worry about it.

The bolt-action rifle leapt to its position of dominance over all other forms of rifles shortly after Paul Mauser perfected his Model of 1898, and not a lot has changed since then. Except in military and certain police applications where sustained semiautomatic or full-automatic fire with smallbore rounds is desirable, the superiority of the turnbolt rifle remains unquestioned. No other action type can offer such a unique combination of benefits: tremendous strength to handle the most powerful cartridges in a relatively lightweight rifle, reasonably fast reloading with a practical magazine capacity, reliable operation in harsh environments, precision accuracy and economy of manufacture which makes possible the widespread availability of a quality product. Nowhere is the strength, reliability or overall efficiency of the bolt-action rifle more important than in dangerous-game hunting where the quick and sure delivery of fast-moving big-bore bullets can be a matter of life or death.

Most of the big-bore rimless cartridges chambered in today’s bolt-action rifles can trace their ancestry back through the first rimmed cordite-fueled Nitro Express cartridges all the way to single and double-barrel blackpowder guns of the turn of the last century. That’s certainly true of the .585 Nyati, which was developed by distinguished gunwriter, shooter and hunter Ross Seyfried on a .577 Nitro Express case modified to fit a magnum-length Mauser action.

The name Nyati, which is the Kiswahili word for Cape buffalo, is not the usual marketing department flight of fancy but accurately reflects the cartridge’s primary target. Nyati is widely considered the most dangerous-to-hunt and toughest-to-kill animal ever recorded in the annals of hunting.

The legendary .577 Nitro Express, with its 750-grain .584”-diameter bullet loaded to 2050 fps for 7010 ft/lbs of energy, was normally chambered in long-barreled double rifles weighing 13 pounds or more. Under normal hunting conditions, the big rifle was seldom used and most often carried by others. But in an emergency situation, say crawling through solid bush toward a wounded and highly annoyed Cape buffalo or stopping the freight-train charge of a raging bull elephant, the .577 was highly prized.

Because of the superiority of a Mauser action over any break-open lock in handling chamber pressure, the rimless .585 Nyati outperforms even its renowned rimmed ancestor. Seyfried claims that a maximum .585 Nyati load can launch a 750-grain bullet at the Cape Canaveral blast-off velocity of 2525 fps for 10,620 ft/lbs of kinetic energy at the muzzle. These published figures are open to some question and factors such as length of the test barrel to arrive at them are unknown. If the figures are accurate, the .585 Nyati exceeds the muzzle energy of 600 and 700 Nitro Express cartridges in factory loads with 900 and 1000-grain bullets respectively, and delivers 175 ft/lbs of recoil energy in a 10-lb rifle. That is almost ten times the recoil of a 30-06, which old-time gunwriters, deer hunters and military shooters used to claim was the limit of human endurance. Based on this energy level, Frank Barnes and the editors of Cartridges of the World compared the recoil of the .585 Nyati to “having a 10-lb. rifle dropped off a 32-foot cliff and catching it with your shoulder.”

Even Seyfried suggests that loadings of the 750-grain bullet at velocities down in the 2200 fps range are more practical. This still translates to more than 8,000 ft/lbs of energy, considerably more than the bruising .460 Weatherby Magnum in its hottest factory load. Lighter bullets of 650 grains can also be used in the .585. Needless to say, the 585 Nyati is sufficiently devastating to bring down in a decisive manner any creature that has ever roamed the planet. But it is not in the nature of African-oriented gunmakers to leave devastating-enough alone.

Both Fred Wells, celebrated custom riflemaker to kings, and Michael Roden, founder of highly respected Granite Mountain Arms, have developed .585 cartridges with overall greater length and case capacity than the Nyati to fit the big Wells Super and GMA African Magnum Mauser actions made by both firms. Case length of the Nyati is 2.79” and both the .585 Wells Express and the .585 GMA Express are almost half an inch longer. This greater case capacity makes the cartridges more versatile. Depending on the powder used, they can be loaded to achieve increased velocity, for those bent on testing the structural integrity of their bullets, or decreased chamber pressure, always an important consideration in hot-weather hunting. The Wells and GMA .585s are almost indistinguishable, with the Wells case sharing the very slightly rebated rim of the Nyati and the GMA case being rimless. Ballistic performance potential of both cartridges should be identical, and beyond the limitations of the shorter Nyati case.

Fred Wells once said with a twinkle in his eyes, “Another benefit of the bigger case, besides more energy and velocity, is that it gives a man something to hold on to when he’s loading his rifle, instead of fumbling around with a little short cartridge. You’ve got something about the size of a cigar there. That’s one reason the English built those big ones, so when a guy was in a hurry to stuff them into a double-barreled gun he wouldn’t drop them.”

For such a specialized gun, there certainly seems to be a ready market. I couldn’t find an unsold 585 Nyati anywhere. Several Fred Wells .585 Wells Express rifles changed hands fairly recently. Mike Roden says he’s been trying to build a .585 GMA Express for his own personal use for years, but every time he completes one somebody insists on buying it. Mike has another one in the final stages of completion which he vows he will keep, and that’s the one I took to the range.

The GMA rifle tested is a quick handling gun with a 22-inch barrel and empty weight of 10 pounds, 14.9 ounces. Mike Roden spent a lot of time personally working on this stock, shaping it along classic English lines and hand-rubbing the finish, with a remarkable beauty and balance as the result. Metalwork benefited from the talented hands of both Stuart Satterlee in Sturgis and Russell Menard in Arizona, with Satterlee concentrating on the barrel-to-action work and Menard on the rail-work and feeding. Load development for the short 22-inch barrel has been a joint effort between Roden and Menard and was still in progress when I took the rifle out for a spin. And I do mean spin.

I fired a 750-grain Woodleigh soft chronographed at 2000 fps (this was easily achieved with 160 grains of H4831 powder, 170 grains of H4831 later increased velocity to 2160 fps), and can report that the recoil impression firing this moderate load from an offhand position was less like shooting a rifle and more like having an out-of-body experience. The recoil didn’t actually hurt. There were no shoulder bruises, no knuckles banged up by the bolt handle or the triggerguard, no blood anywhere, and that is quite a testimonial to the stock and overall design of the rifle. It’s just that when the sear dropped everything went blank, a state I assume lasted only a split-second but there was no sensation of passing time. The closest thing in my experience was a high-speed spin-out in a formula race car whose suspension was so finely tuned to the absolute limit of adhesion that there was no indication whatsoever that the car was about to go before it went. One ounce of g-force over the invisible line and you just found yourself sitting in a parked car facing the wrong direction enveloped by a cloud of dust and debris with no idea how you got there. That’s how the .585 felt in recoil.

In racing, the solution is either to develop the magical sensibilities top formula car drivers must have or to move down to conventional racing machines that let you know what they’re about to do before they do it. In the case of the .585, it doesn’t really matter as long as you have the proper sight picture before your psychic journey begins. Experience should help you build confidence that this is so, though extensive experience in the cockpit of a .585 is an expensive thing to acquire.

Russell Menard, a big strong guy who shoots his own 16-pound .50 BMGs offhand for fun, uses the recoil-absorbing Caldwell Lead Sled for developing loads and sighting in the .585 from the bench. He says, “When I was younger I told everybody I would shoot anything I could hold in my hands. After working with the .585, I’ve decided I really don’t need anything bigger than this.” In his typically understated fashion, Larry Barnett at Superior Ammunition, who will happily develop custom loads for any cartridge known to man, says, “There’s plenty of horsepower in any of those three .585s for anybody who wants it.”

But is plenty ever enough? Fred Wells once told me that Kynoch was developing a rimless .600 Nitro Express case for him, because he intended to fill it with a 900-grain bullet and plenty of powder and stuff it into a custom Mauser action. I can imagine pulling the trigger on that one. Leaping out of your body for an indeterminate period of time can become addictive.