November 13, 2015
By John Geiger
Hornady is serious about making sure any friction heat does not melt or deform the bullet tip in any way. That's why they developed a new polymer that they are calling their Heat-Shield Tip. They claim it resists melting even up to 700 degrees while traditional polymers melt at less than 350 degrees.
Bullet-makers agonize over every little curve, every nano-measurement of the ogive, cannelure and me plat. other aspects that most hunters don't even know exist.
But what about that big old plastic tip? Had anyone paid that much attention to that? According to engineers at Hornady Ammunition , no.
"Their tips are melting," said Dave Emary of Hornady. "Our tips are melting, too."
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Emary said the polymer tips of bullets that travel over long distances at high speeds are literally deforming in flight and literally, melting on their way. As you could imagine, that disrupts the slipperiness of the bullet, which is key to accurate flight.
"That increased the meplat diameter, the point of the bullet, and the ballistic coefficient (BC) dropped while the aerodynamic drag increased," said Jayden Quinlan, ballistics engineer.
Hornady's answer to this problem is a new ELD-X bullet that uses a polymer that resists melting. They're calling it their Heat Shield Tip, and they're topping a newly designed long-distance bullet with it. The Hornady ELD-X, short for Extremely Low Drag Expanding, also has several other features that make it an excellent choice for long-and close-distance shooting.
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From the muzzle to about 400 yards, the Hornady ELD-X bullet is designed to continually expand through the game animal, remain intact and resist tumbling. Out past 400, the Heat Shield Tip drives backward into the redesigned nose cavity to start expansion even at lower velocities.
ELD-X bullets will be loaded into a new cartridge called Precision Hunter, and available in early 2016. The bullets will only be used in 6.5mm to .30-caliber range, that is, those that reach high speeds quickly and retain them.
According to the company, there is no plan to replace all of their polymer-tipped bullets with the Heat Shield Tip, although that may happen in the future. They said lighter bullets that have high velocities, like their V-MAX varmint bullets, lose those velocities quickly. The tips don't have time to melt and deform aerodynamics, according to Emary, who is chief ballistician at the Nebraska company.
DOPPLER DOUBLE-TAKE
This Extremely Low Drag-eXpanding, or ELD-X, bullet was fired into gel to simulate expansion at 800 yards. "If we wanted to build just a long-range bullet, that would have been easy," said Neal Emery of Hornady. "This is an all-range bullet."
A few years ago, engineers started using ultra-precise Doppler Radar to measure bullet flight characteristics from the muzzle until it hit a distance target. At first, they did not get the numbers they were seeking. The BC or ballistic coefficient was about 15 percent lower than they expected.
When they took a closer look at the Doppler data, they concluded that the bullet must actually be changing shape a different points during the flight. After floating and dismissing several theories, they realized that the plastic tip would be melting if the bullet reached high velocities for a period of time, specifically 800 degrees for more than a second or two.
"And that's when the light bulb clicked on," said engineer Joe Theilen.
They tried a different, heat resistance polymer, and got dramatically better performance with the same bullet, propellant, caliber and gun.
The simple change — €¯from one polymer to another — €¯is the reason long-range shooters will be able to likely improve their groups.
Hornady will be offering eight long-range calibers from 6.5mm Creedmoor to .300 Rem Ultra Mag to start. They are expected to cost about $40 per box of ammo in the .30-caliber range.
TIGHT GROUPS
This gel shot shows just want you want in a long-range bullet: an extensive temporary wound cavity, predictable expansion and a good 2 feet of penetration.
At the range, engineers shot 4-inch groups at 930 yards. At 200 yards, count on .5 MOA, if your gun is capable of it.
I was impressed at the long-range accuracy of these new bullets. I shot a .300 Win Mag at steel targets from 100 out to 1,100 yards and was astounded at the accuracy.
Gels tests showed phenomenal expanding characteristics at short and long ranges. The bullet stubbed down to the core and retained the mushroom shape at even long distances where velocities and energy were dissipating. It produced violent, gapping temporary wound cavities and penetrated to about 24 inches before stopping.
Another demonstration of the effectiveness of the new Heat Shield Tip was revealed when Hornady measured the Ballistic Coefficient of bullets with the new tip as compared to the old tip. The company's 6.5 140-gran A-MAX traditionally has a published BC of.585. But when Hornady checked it with Doppler radar, it actually had a BC of .545 at long distances said Emary. That's a huge jump in aerodynamics of what was already a very accurate bullet.
