Show Me The Data, Or, Why I Like Berger Bullets

I have been reloading for as long as I have been seriously involved in the firearm world, and I have over time gravitated to using three brands of projectiles for rifle shooting: Barnes, Berger, and Sierra. I like Barnes’ Match Burners because they’re priced lower than the competition, but even so they shoot very well, allowing me to shoot more often with the same amount of money. I like Sierra MatchKings because they’re available in a million flavors and I am able to find them almost everywhere I go – plus they’re used in a lot of factory ammo, allowing me to play the fun game of “with the same bullet, are my handloads better than factory ammo?”

Bergers? I like Berger bullets because they shoot insanely well, but I really like Berger as a company because they are all about sharing data. Berger not only provides sectional density, G1 and G7 ballistic coefficients, and other data for every bullet they make in one handy document, but they also provide form factors – and their chief ballistician, Brian Litz, writes easy-to-understand explanations of why these things are important.

I highly recommend digesting Mr. Litz’s articles, but for those who don’t have the time or inclination to read them (or some other articles which also cover the topics at hand), I will summarize ballistic coefficients and form factors as best I can here.

Ballistic coefficient (BC) – a number representing the relative ability of a projectile to maintain velocity. Relative to what? A “standard projectile.”
Standard projectile – a defined projectile shape used as a benchmark for velocity retention, against which all projectiles of a similar shape may be compared.
Sectional density (SD) – ratio of mass to frontal area. While often used to determine the terminal effectiveness of a projectile, in external ballistics terms, this number is used along with form factor to calculate ballistic coefficient.
Form factor – the drag of a projectile divided by the drag of a standard projectile. This number represents the efficiency of the shape of the projectile regardless of its weight.

Why is form factor important? Consider two bullets with the same ballistic coefficient but different weights. The heavier bullet would only be as efficient (that is, have as flat a trajectory) as the lighter bullet if it was pushed to the same velocity. But since we can generally make lighter bullets go faster, the lighter bullet with the same ballistic coefficient will have a better trajectory. This is form factor: the heavier bullet might be 3% less efficient than a standard projectile, or a form factor of 1.030, while the lighter bullet might be 5% more efficient than the standard projectile, or .950. Why shouldn’t a shooter try to calculate the relative efficiency of projectiles and use that as part of their decision making process? Beats me. For a list of some Berger form factors, click here.

Earlier I mentioned BCs, and many of you may have seen these numbers advertised on boxes of bullets or even loaded ammunition. Shooters use ballistic coefficients to estimate trajectories for their chosen ammunition. Most bullet manufacturers use a G1 BC, which references a standard projectile which is (literally) straight out of the 1800s.

Since a ballistic coefficient is a comparison of the ability of a projectile to maintain velocity compared to a standard projectile, the use of a relatively inefficient standard projectile shape will give the false impression of a numerically higher ballistic coefficient. Put simply, the G1 standard projectile’s inefficient shape causes it to shed velocity faster than other shapes. However, most rifle bullets are so much smaller than the standard projectile diameter and weight of one inch/one pound that even a more efficient shape cannot make up for being smaller. So the ballistic coefficient of essentially every rifle bullet will be much less than 1, where 1 is equal to the BC of the standard projectile.

The basic problem with using a G1 BC is that the inefficient but large standard projectile and the efficient but small projectile we’re trying to estimate a trajectory for are not going to fly through the air in the exact same manner at all velocities. Because they’re different shapes, they will behave differently. The two ways to address this are to 1) attempt to calculate multiple ballistic coefficients for a velocity “window,” inside which the efficient projectile should behave kinda-sorta in a manner relative to the G1 projectile at that same velocity (which is what Sierra does), and 2) use a standard projectile shape which is similar to the projectile we’re trying to estimate a trajectory for (which is what Berger does). The standard projectile which most closely approximates modern boat-tail projectiles is called G7.

Both approaches work when used correctly. The problem with Sierra’s approach is that it is unwieldy and requires entering multiple sets of data to retrieve a single result. The problem with Berger’s approach is that because the G7 standard projectile is larger than an average rifle bullet and theoretically about as efficient, the resulting “G7” ballistic coefficient will be numerically lower than a “G1” BC for the same bullet.

Put simply, a G7 BC looks unimpressive when one has only seen G1 BCs. The payoff, though, is a much more accurate trajectory than using a single G1 BC, and simpler calculations than when using multiple G1 BCs. From an objective standpoint, I see little reason but marketing to continue selling boat-tail projectiles under a G1 BC calculation.

So why do I like Berger bullets? Because not only do they market their products in the most transparent manner possible, but they use their research in these areas to create the most precise, accurate, and efficient bullets possible. Perhaps most importantly, when they make an error, they quite graciously announce it and what they’re doing to fix the problem.

I wish more companies in this industry were like Berger.