volume 11.2

Terry Wieland’s On Ammo

The .577 Tyrannosaur: A-Square’s Behemoth Fills A Need. Sort Of.

The .577 Tyrannosaur is not one of the classic nitro-express cartridges. In fact, designed in 1993, it is barely a dozen years old. It was created by Art Alphin, then-owner of A-Square, at the specific request of some of his Zimbabwean professional-hunter friends.

Although only a few score Tyrannosaur rifles have been made in that time, the cartridge is worthy of attention for several reasons:

First, it delivers power like very few others and, second, it does so at a fraction the price of anything else in its class. Finally, it offers rifle-lovers of reasonable means the opportunity to play with one of the most interesting of all bullet diameters - the .577.

The original .577 Nitro Express is a rimmed cartridge that has been around for more than a century. One can still buy a .577 double rifle from H&H or Rigby, but it will cost big bucks, and used .577s also command a premium price. This is a problem for the PH of modest means whose work involves elephants, because the .577 NE is an elephant cartridge par excellence, renowned for its penetration and knockdown power.

As Art tells it, he was approached in 1993 by two Zimbabwe PHs who had experienced serious problems with elephants while armed with .458 Winchesters. They wanted something bigger - much bigger. Could Art build his Hannibal dangerous-game rifle in .577 or even .600 NE?

True to form, Art tried to talk them into a .500 A-Square, a heavyweight based on the .460 Weatherby belted case that out-performs the .500 Jeffery. No, they said, we want .577s or .600s. Although either is technically possible, Alphin then suggested another alternative: He would design a rimless cartridge that would fit and feed better in his bolt action, and create a more powerful rifle. Then, A-Square would supply factory ammunition loaded with both solid bullets and soft points.

Because he was not using an existing cartridge as the basis for his creation, Alphin had free rein to put his undeniable ballistic talent to work. The result was a cartridge designed specifically to work in one action (the Enfield P-17, the basis for the Hannibal model) and, as a result, will fit any true magnum bolt action. It is rimless, with a base diameter that dwarfs even the .460 Weatherby (.688” vs. .579”). It does not have a rebated rim like the .500 Jeffery, and it has a small but sharp and definite shoulder for proper headspacing.

As A-Square loads the cartridge, it fires a 750-grain bullet at 2,460 feet per second, for muzzle energy of more than 10,000 foot-pounds. For the record, the case will hold 180 grains of H4831! No other company loads the cartridge or makes the brass, but since brass, bullets, and loaded ammunition are once again readily available from A-Square, securing a supply is less difficult than for many other big cartridges.

Jim Smith, the new owner of A-Square, says the first question anyone asks about the Tyrannosaur is “What’s the recoil like?” Since there are a couple of videos floating around the internet showing several people being thrown across a room when firing it, your long-suffering correspondent would like to assure you that it simply is not like that.

The Hannibal rifle employs Art Alphin’s “Coil-Chek” stock, which minimizes recoil in heavy cartridges through proper stock design rather than gadgets like muzzle brakes and recoil reducers. However, Art conceded the Tyrannosaur needed something more and put three reducers in the stock. So equipped, it weighs about 13 pounds.

Jim and I took a Tyrannosaur to the range and four of us tried it out. I fired two shots in succession. I was rocked onto my back foot, but not thrown off balance, much less out of a window. The trick is to make sure you have a solid, offhand shooting stance, and take a very firm hold on the fore-end.

What is such a rifle good for? Only one task I can think of: Dispatching elephants at close range under perilous conditions, and even then, only by a man with muscle.

At the same time, a handloader could have a lot of fun with it, loading lead bullets ahead of a few grains of XMP5744. Recoil would be nonexistent, and it would be a fine deer and bear rifle for anyone with the strength to carry it.

In light of all this, you would think orders for the $4175 Hannibal in .577 Tyrannosaur would be few and far between. However, there are 50 or so in use already, and A-Square has orders for a half-dozen more Tyrannosaurs - more than for any other single calibre. Ammunition is $159 for a packet of 10. I leave you to draw your own conclusions.

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A-Square Factory Loads
Velocity Energy

750-grain Monolithic Solid 2460 fps 10,080 ft.lbs.
750-grain Dead Tough ” ”
750-grain Lion Load ” ”

· Velocity measured from a 26-inch barrel.
· A-Square Triad ammunition shoots all three bullet types to same point of impact.

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