Share Facebook

Twitter

Pinterest

As long-range shooters, we tend to obsess over every little detail. After all, we’re trying to hit relatively small targets that are so far you may not even be able to see with the naked eye. While you might can get away with minor mistakes and still ring steel at short and medium ranges, as you extend the range those small mistakes or tiny inconsistencies are magnified. So, most things are important … but to differing degrees. This series of posts is taking a data-driven approach by using Applied Ballistic’s Weapon Employment Zone (WEZ) analysis tool to gain insight into how different field variables in real-world shooting affect the probability of hitting long-range targets.

I’ve played around with the WEZ tool a lot, and it was very enlightening! It challenged a lot of my long-held assumptions about how important different aspects were. As Bryan Litz said in his Accuracy & Precision for Long-Range Shooting book, “Looking at each variable separately teaches us how to assess the uncertainties of any shot and determine how critical each variable is to hitting the target.”

Previous posts looked at what impact we could expect from tightening our groups, and what we could expect from lowering our muzzle velocity SD. In this post we’ll look at another element that we handloaders tend to fixate on:

How Much Does Cartridge Matter?

Honestly, I’d be embarrassed if you knew how much time I’ve spent agonizing over cartridge selection. We love to get the absolutely highest performing bullet in the ideal case, even if that means we might have to fire-form brass and handload it ourselves. So I wanted to see how much of a difference that has on hit percentage at long-range. This is highly dependent on the loads you’re comparing, but we’ll compare a couple of the most popular rounds: the 6.5 Creedmoor and the 6mm Creedmoor. I’m also going to throw in the 308 with 175gr SMK bullets. The 308 isn’t as popular as it once was in long-range shooting, and a lot of new shooters might not understand why. This should help illustrate a big part of that. And I’m going to throw in one of the newest cartridges, a hot-rod 6.5mm cartridge known as the 26 Nosler.

Note that the external ballistics for the 6.5 Creedmoor are very similar to the 260 Rem and 6.5×47 Lapua, so you can replace 6.5 Creedmoor with one of those names if you would like. Likewise, the 6mm Creedmoor provides external ballistics very similar to the 6XC, 6×47 Lapua, and 243 Win … so you can easily replace 6mm Creedmoor with one of those cartridge names as well.

6.5 Creedmoor

Bullet: Berger 140gr Hybrid with a Litz G7 BC of 0.320 (one of the best 6.5mm bullets available)

with a Litz G7 BC of 0.320 (one of the best 6.5mm bullets available) Muzzle Velocity: 2850 fps (the upper end of what top PRS shooters using the 6.5mm Creedmoor reported, although many don’t run it this hot)

6mm Creedmoor

Bullet: Berger 105gr Hybrid with a Litz G7 BC 0.278 (outstanding bullet, very high BC relative to its weight … read more on why everyone uses this bullet)

with a Litz G7 BC 0.278 (outstanding bullet, very high BC relative to its weight … read more on why everyone uses this bullet) Muzzle Velocity: 3100 fps (the upper end of what top PRS shooters using the 6mm Creedmoor reported, although many don’t run it this hot)

308 Win

Bullet: Sierra 175gr SMK with a Litz G7 BC 0.243 (a popular bullet choice when stretching the 308 into this 700-1000 yard range)

with a Litz G7 BC 0.243 (a popular bullet choice when stretching the 308 into this 700-1000 yard range) Muzzle Velocity: 2600 fps (advertised muzzle velocity for the popular Federal Premium ammo with this bullet)

26 Nosler

Bullet: Berger 140gr Hybrid with a Litz G7 BC of 0.320 (one of the best 6.5mm bullets available)

Muzzle Velocity: 3300 fps (Nosler’s reloading data for this cartridge indicates this cartridge has the potential to run this fast … that’s 15% faster than a hot 6.5 Creedmoor load running that same bullet)

For all the loads, we’ll assume we were able to achieve an great muzzle velocity standard deviation of 10 fps (see the previous post for more info on what that means). We’ll also run all of the simulations at a 0.25 MOA extreme spread, and good wind-calling ability, which means we’re able to call the wind speed within 1.25 mph 68% of the time, and within 2.5 mph 95% of the time.

Here is how it shakes out:

The first thing that pops out is the huge difference between the 308 and the other cartridges. While this isn’t a surprise to veteran shooters, it may be to some of the new guys. This is one of the big reasons there aren’t a lot of shooters running a 308 at a competitive level. The only real exception is those classes of competition that explicitly require shooters to use a 308 cartridge.

But, then we have more of a head-to-head comparison of the 6.5mm Creedmoor cartridge with the best bullet available and the 6mm Creedmoor with the best bullet available. You can see there is just a 1% difference between the 6.5 Creedmoor and 6mm Creedmoor at these ranges. That means if you fired 100 rounds, you might hit one more time with one cartridge … they’re the same for all practical purposes. Both are an massive improvement over the 308 (with significantly less recoil as well), and represent best-of-class ballistics for medium size long-range cartridges. The difference is the 6mm Creedmoor gives you those ballistics for much less recoil, but at the cost of slightly less barrel life.

And finally, the hot-rod 26 Nosler launching a 140gr bullet like a laser beam at 3,300 fps!!! To get that requires almost 90 grains of powder. While the accurate barrel life of that cartridge may be less than 1,000 rounds … it represents best of class ballistics. I ran a few other cartridges, and found a 7mm magnum (like the 7mm Rem Mag or 7mm WSM) launching a 168gr bullet at 3,000 fps produced almost identical results when you used the new Nosler Accubond Long-Range 168gr bullet with a G7 BC of .353 (G1 = .652). If that advertised BC is correct, that’s even higher than Berger’s 180gr Hybrid … but in a 168gr bullet. The 7mm Magnum option may provide slightly more barrel life, but not a lot more. Those are just smoking ballistics, and the cost to get there is less barrel life and more recoil. Even a 338 Lapua doesn’t produce a better hit percentage at those distances.

One last point to keep in mind, is that all of this analysis assumes you have centered groups. That means they represent the best case scenario for hit percentage, since your odds only decrease if groups come off center. If you’re scope isn’t zeroed, or your rifle is canted slightly to one side, or your scope’s clicks aren’t calibrated correctly, or you pull the shot slightly … then your hit probability can decrease dramatically. But these simulations assume we have all that stuff squared away.

Other Posts In This Series

This post was one of a series of posts that takes a data-driven look at what impact different elements have on getting hits at long-range. Here are some others posts in this series:

If you want to dig more into this subject or explore some of these elements for your specific rifle, ammo, and ballistics, I’d encourage you to buy the Applied Ballistics Analytics Package to run these kinds of analysis yourself. You could also pick up Bryan’s Accuracy and Precision for Long-Range Shooting book, which has a ton of great info on these topics and other aspects of shooting.

Enjoy this type of data-driven information? That’s what this website is all about. Sign-up to receive new posts via email.

© Copyright 2020 PrecisionRifleBlog.com, All Rights Reserved.