Ballistics Test: The Best Big Game Bullets
March 05, 2014
One of the hallmarks of a great big game bullet is its ability to offer good terminal performance from very close range to long range. Almost any bullet can be made to expand at long range, but the thin jackets and soft cores that promote such expansion don't support bullet integrity when impact distances are close and velocities extremely high.
Conversely, it's not that difficult to produce a bullet that will hold together at close-range, high-impact velocities, but the heavy jackets, harder lead-alloy cores and bonding processes used to create such bullets can inhibit expansion when distances stretch and velocities drop.
It takes a lot of research and development and field research by a good team of engineers to design a bullet that will both expand and hold together through a wide range of velocities.
Granted, for 80 percent or more of the game (whitetails) shot by Americans, bullets don't really need to hold together and penetrate particularly deeply to provide clean, humane kills. Classic, soft, cup-and-core bullets perform beautifully on deer-size animals. They typically expand violently, causing tremendous wound cavities and resulting in rapid kills.
If they penetrate only 12 or 14 inches (inhibited by that same massive frontal diameter that's causing such dramatic tissue destruction), that's usually adequate. Heck, few whitetails, antelope, mule deer and even average black bears measure much more than 12 inches broadside through the vitals. It's when game such as elk, moose, caribou, mountain goats and the bigger bears are on the menu that bullet integrity becomes critical.
On such heavy-bodied game animals, which are challenging to hunt and rarely offer a perfect broadside presentation, I'm a believer in using premium, heavy-for-caliber bullets. They typically expand well through a wide velocity window yet hold together well for deep penetration on animals that measure 20 inches or more through the vitals- on a perfect broadside shot- and offer capable penetration if a quartering-to shoulder shot or a quartering-away raking shot is all that's offered.
How to choose one of the myriad premium bullets available today? To throw a little light on the subject (and out of my own curiosity), I recently shot a selection of eight of my favorite bullets into 10-percent gelatin at 50 and 400 yards. The results are chronicled and analyzed here, beginning with criteria.
It wasn't hard to choose a bullet diameter and weight and a cartridge through which to test it: America is still a .30 caliber nation; 180-grain projectiles typically offer excellent sectional density and ballistic efficiency; and the .300 Win. Mag. is both capable and popular, especially on the heavy-bodied game where bullet performance becomes critical.
As for distances, I'd already decided to choose 50 yards as the close mark, and after some discussion the editor settled on a max of 400 yards- a long shot, for sure, but a range at which most accomplished riflemen can make clean, ethical hits from field positions.
Most of the professional ballisticians I've spoken with agree that a projectile's rotational velocity has little effect on impact expansion. However, some point out that since rotational velocity maintains itself much longer than downrange velocity, it must, to some extent, affect expansion via centrifugal force.
Therefore, rather than simply loading down to simulate 400-yard impact velocities (which has the unavoidable side effect of reducing rotational velocity), we set gel blocks out at 400 yards and shot them.
The following photographs of our test subjects show an unfired bullet, a sectioned bullet and a bullet recovered from gel at 400 yards and a bullet recovered from gel at 50 yards. Take a look at the bullets themselves and what we learned. Data are also found in the accompanying charts.