Why Hunters Prefer High Ballistic Coefficient Bullets
February 25, 2015
My favorite guitarist, the late Jerry Garcia, once said, "On this planet, louder is better." And so it is with hunting cartridges in America: Most hunters believe faster is better.
All things being equal bullet-wise, a faster projectile shoots flatter and is less affected by wind. That in turn makes it less likely errors in range or angle estimation or wind reading will result in a miss or wounding hit. And the bullet will have more muscle behind it when it arrives on target.
There are two ways to get downrange speed: Push the bullet faster at the start — the magnum route — or use a bullet with a high ballistic coefficient in order to retain speed better.
For those who aren't familiar with BC, it's a way to measure how well a bullet handles air resistance. A sleek, boattailed, sharply pointed bullet has a higher BC than, for example, a lead-tipped roundnose and won't slow as quickly as it travels downrange.
Last year my wife and I traveled to Kazakhstan to hunt Mid-Asian ibex. I decided to take the .280 Rem. I've owned for decades and have recently been upgrading. Now, the .280 is no speed demon, and I knew from editing Craig Boddington's work over the years that Asian mountain hunting can bring shots on the long side — like 400 yards and even farther. While I hoped to avoid shooting such distances, I did want to reduce wind drift and also maximize on-target energy because, as Craig reminded me when we discussed the trip, ibex are tough critters.
If you're a .280 Rem. shooter you know there's not exactly a ton of choices in factory ammo, so most of us reload it. And that was a good thing in this case because it allowed me to try two relatively new bullets designed specifically with ballistic coefficient in mind: the Nosler 150-grain AccuBond Long Range (ABLR) and the Barnes 145-grain LRX.
The Nosler's BC is a whopping .611 (G1 model). Nosler also gives the G7 model figure — which some long-range shooters feel is a better representation of BC at distance — as .309. The LRX has a G1 BC of .486, and it's worth noting Barnes derives its BC figures at 300 yards. (Bullet BCs change as the bullet slows, which is why companies such as Sierra list different BCs for different velocities for the same bullet.)
The solid copper LRX was introduced in 2011, and it's a version of the Tipped Triple Shock (TTSX). But it's not just a longer, heavier TTSX. As Barnes's Brett Throckmorton explains it, to optimize the bullet for long range, designers adjusted the ogives to be more secant (you can look that up), the boattails were made longer and the bullet shank cannelures were adjusted to boost BC. Internally, the LRX's cavity was modified so it would open properly at slower speeds; even with a high BC the bullet will be moving relatively slowly at really long range.
One of the great characteristics of the Barnes X bullet and its successors has always been high weight retention, and with the LRX that doesn't change.
"Negating the tip, shooters can expect to see nearly 100 percent weight retention with the LRX," Throckmorton says. "However, if you find yourself in a situation where you are shooting an animal at 40 yards with a .30-378 Wby. and the 175-grain LRX, that bullet will most likely shed a petal or two, but not before fully expanding. So it will still do its job and still retain around 80 percent of its original weight."
The knock against the original X was that some rifles didn't shoot it well, but changes in design that debuted with the Triple Shock and TTSX — most notably the shank cannelures that reduce bearing surface, a change carried on in the LRX — have made finicky accuracy less of a problem.
I got excellent 100-yard three-shot groups with the 145-grain LRX with both Reloder 19 and Reloder 22, but at 200 yards the Nosler ABLR proved to be more accurate in my rifle. I do plan on working more with the LRX, trying more powders and experimenting with seating depths (the company advises starting with 0.050 inch of bullet jump).
The ABLR bullet, introduced in 2013, is based on the company's AccuBond, and like the LRX, it isn't just a heavier and longer version but one redesigned for high BC. Nosler's Zach Waterman says the ABLR has a longer boattail and a slowly tapered, tangent ogive (again, look it up; the concept of tangent is too much for a non-math person like me to explain in a short article) for each caliber and weight.
Since the ABLR design features a copper jacket bonded to a lead core, unlike the monolithic LRX, two other design aspects had to be changed.
"The AccuBond has a thicker jacket at the nose, which gives it a minimum impact velocity of 1,800 fps," Waterman explains. "Since the ABLR was designed for shooting at longer ranges, it has a thinner jacket at the nose and a large hollow cavity behind the polymer tip, which allows the ABLR to have a minimum impact velocity of 1,300 fps for effective terminal performance at long distances. The ABLR has a maximum impact velocity of 3,400 fps.
"The ABLR is designed to have 50 to 70 percent weight retention, depending on impact velocity," he says. "Since the ABLR has a much softer nose and larger nose cavity than the AccuBond, weight retention tends to be 50 percent at maximum impact velocities of 3,400 fps and 70 percent or more at 2,500 or slower."
I killed my ibex at a reasonable 250 yards, at which point my bullet would've been traveling a touch faster than 2,600 fps. We found the bullet on the far shoulder, just under the hide, and it weighed 100.7 grains. That's about 67 percent weight retention — in line with what the bullet should do — and you can see from the accompanying photo it produced a good mushroom and frontal area.
I recently read an article that basically said these super-high BC bullets aren't gaining you anything. I disagree. Certainly they won't take a pedestrian cartridge and turn it into a death ray. My ibex ABLR load — a max charge of Reloder 22, Nosler case, Federal 210 primer — leaves the muzzle at 2,936 fps on average. It drops only 6.2 inches at 300 yards and just 17.8 inches at 400 yards; drifts 3.8 inches at 300 and 6.8 at 400; and generates respective energies of 2,199 and 2,006 ft.-lbs. at those distances (based on 200-yard zero, 5,000 feet elevation, 50 degrees, 10 mph wind, 78 percent humidity).
By my calculations, I get about a seven percent increase in velocity and energy at 300 yards over what I would've had with a standard BC bullet of the same weight. And I get it without incurring extra recoil and muzzle blast, which I count as a win. The increase also gave me added confidence that a cartridge most people wouldn't choose for such a hunt would work just fine if I did my part.