January 04, 2011
By Wayne van Zwoll
's new Superformance ammo delivers more--with less.
By Wayne van Zwoll
The biggest jump in cartridge engineering since smokeless powder? Hornady's Dave Emary isn't given to hyperbole, but when it comes to talking about the company's new Superformance centerfire ammunition, what he outlines sounds like a tall order indeed.
"It's true. Higher velocity under SAAMI pressure limits," he says. "No, we don't compress the powder. And it's shedding just 18 fps per inch of barrel when we chop a .300 Winchester Magnum to carbine length--half the loss of ordinary loads. And Superformance rounds behave the same at 15 below as at room temperature."
Over the years, Hornady has become a major player not just in ammo manufacturing but also cartridge design--scoring successes with in-house-developed cartridges such as the .17 HMR and the LeverEvolution line of lever-action powerhouses.
For years Hornady had also been hard at work on boosting the performance levels of bolt-action centerfire hunting ammo meant for big game.
"We launched our Light Magnum line in 1995 after I saw at Olin-St. Marks how to build extra-powerful loads in ordinary cases without exceeding safe pressures," Dave says.
But the ball powders had to be compressed, boosting cost of manufacture. The heavier charges also increased recoil. And some cartridges didn't lend themselves to turbo loads. As a result, Hornady's Light Magnum and Heavy Magnum (belted) rounds remained a minor segment of its ever-expanding line of ammo.
More recently, company engineer Mitch Mittelstaedt worked with Dave in adapting new propellants to cartridges designed for short-action bolt-action carbines, creating the .300 and .338 Ruger Compact Magnums.
Now the company has topped all that with its Superformance ammo line. Emary calls it the most significant hike in centerfire performance since standards were set with IMR propellants in the 1930s.
"Dave and his crew have found a way to apply what they've learned from LeverEvolution and the Marlin Express and RCM cartridges to ordinary ammunition," company president Steve Hornady says. "No other sporting ammo can come close. Superformance delivers higher speeds, flatter flights, less recoil and lower pressures than its competition. It's as accurate as any ammo we've ever made, less temperature-sensitive and more efficient in short barrels. It will cost less than cartridges souped up with compressed charges."
The preliminary list includes 28 loads, from the .243 Winchester to the .458 Winchester Magnum. All share the Superformance feature that sets this line apart: ball powders chemically and physically treated to deliver a smooth, steep but flat-topped pressure curve that pushes bullets quickly from the case, accelerates them smoothly down the bore, then drops off decisively.
Low muzzle pressure, even in short barrels, means you get less blast, and less energy is wasted at exit. Superformance loads match the ballistic thrust of Light and Heavy Magnum ammo, but with powder charges 10 to 15 percent lighter, says Emary.
One drawback of the Light and Heavy Magnums (which will be discontinued) was the costly compression step to cram in the powder necessary for top bullet speeds. Superformance loads are engineered for full-case but not compressed charges.
"Our tests show an increase of 100 to 300 fps over standard loads," says public relations man Steve Johnson. "Recently we compared Superformance with two other well-known types of ammunition in a Model 70 .270. We got 3,100 fps from that 22-inch barrel with Superformance 130-grain loads. Same-weight bullets from the other makers clocked 2,920 and 2,780."
Who says you can't get something for nothing? Superformance ammo produces higher velocities without a noticeable increase in recoil.
Tested in temperatures from minus 15 to 140 degrees confirm that Superformance powders don't care a great deal about the weather. Some loads show no velocity change from room temperature to below zero, according to Dave. He says all demonstrate greater consistency than traditional loads. "We've even found them to show less sensitivity to variations in bore diameter."
The propellants in Superformance ammunition are not available to hand-loaders. Manufactured by St. Marks in Florida, they undergo chemical tweaks and degrees of crushing to meet defined burning characteristics. "We also do some blending of powders here at Hornady," says Steve Johnson. "Anyone trying to duplicate our efforts or back-engineer our propellants would take two years doing so."
Initially, Superformance ammunition will feature Hornady's polymer-tipped SST bullet and the company's new lead-free GMX.
Getting enough Superformance ammunition to test in time for this issue of Rifle Shooter proved a challenge because the company was still finalizing the loads, but I managed to wrangle a box of .30-06 and one of .270. Both were loaded with GMX bullets (165 and 130 grains, respectively).
By the time they arrived, I was afield on another assignment. My amigo Sam Shaw agreed to do the chronographing. He unlimbered two pre-64 Model 70s, the .30-06 a Featherweight with 22-inch barrel, the .270 with standard 24-inch. Both rifles shot acceptable groups, but I got better accuracy finishing off the small batches of ammo with a custom Model 70 .30-06 with a Lilja barrel and a T/C Venture in .270.
The following results were recorded on a PACT chronograph. The air temperature was 55 degrees; elevation was 1,500 feet above sea level.
Superformance proved acceptably accurate in a pre-64 Winchester 70 in .270 but shot better out of a T/C Venture.
Hornady Superformance .30-06, 165-grain GMX
M70 Winchester, 22-inch barrel
Average velocity: 2,854 fps
Standard deviation: 6.6
Hornady Superformance .270 Win., 130-grain GMX
M70 Winchester, 24-inch barrel
Average velocity: 3,148 fps
Standard deviation: 7.0
The .30-06 Superformance loads clocked 50 fps faster from a 22-inch barrel than standard '06 bullets from a 24-inch barrel. The .270 Superformance ammo beat nominal speed for standard loads by 120 fps and almost matched Hornady's 130-grain Light Magnum.
The boost in velocity is significant. And with a consequent edge in energy and a flatter trajectory, these loads set a new standard for long shooting. Priced just a dollar or so higher than ordinary ammo, Superformance cartridges are truly super.