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Life After .308 Win And The Future Of Long Range Rifle Cartridges

by Shotgun News Staff   |  July 26th, 2017   |   0
Life After 308

The future is now for long-range shooters: 6.5mm Grendel, 6.5x47mm, 6mm Creedmoor, 6.5mm Creedmoor, .260 Rem., 7.62x51mm NATO, 6.5x55mm and .300 Win. Mag.

There comes a time every few generations where significant developments in firearms technology cause sweeping changes in specific segments of the market.

Looking at the big picture in cartridge development history, we are in a very exciting and transformational era in long-range cartridges. With that in mind, let’s look at where we’ve been and where we’re headed with long-range cartridges as we progress into the 21st century.

Formative Years

I grew up shooting rifle cartridges that were driven by the Western high deserts of the United States and its wide open spaces. These included the .270 Win., .257 Roberts and .264 Win. Mag. As I prepared for military service throughout my adolescence, I read everything I could about military sniping and long-range shooting.

This included books on Carlos Hathcock. From these “studies”, I learned that a .308 Win. was the preferred long-range rifle cartridge for military snipers. In the right hands, it was capable of even reaching out to 1000 yards.

After joining the U.S. Army as an 11B infantryman, I found myself in my second Scout Sniper Platoon on the DMZ in Korea. Here I had the opportunity to receive some Level II SOTIC (Special Operations Target Interdiction Course) training from a split Special Forces A-Detachment out of Okinawa.

The most important skill I learned and embraced in that training was not shooting, but reading the wind. I spent a lot of time behind a spotting scope watching 173-grain M118 projectiles fly downrange in that course.

I was surprised at just how slow and high the M118’s trajectory is. I commented to the SF instructor, “It looked like someone just threw a rock at the target.” His response, “That’s .308 for you.” It was at that moment, watching the vapor trail as the bullet flew onto the 400-yard iron maiden and splashed, when the .308 fell hard from its pedestal in my mind. This was not the long-range cartridge that was advertised, especially at 800–1,000 yards.

Lessons Learned with 7.62 NATO M118

Despite its lackluster trajectory and susceptibility to being blown all over by the wind, we could get a lot of trigger time with M118 on heavy M24 rifles. We did not experience rapid bore wear with this combination, as we did with magnum cartridges. This is an extremely important consideration for any organization actually wanting to provide trigger time for its shooters, and a major benefit to the .308 Win.

By the time I made it to my 3rd Scout Sniper Platoon at Fort Lewis, Wash., it had become clear we needed something with a flatter trajectory and improved wind-bucking capability. The .308 Win. is very unforgiving in the wind past 700 meters. Hit probability went way down once you got past 600 meters, even shooting from bipod prone with a rear bag.

Several years later, I started shooting competitively, focusing first on military two-man team sniper competitions in field conditions with unknown distance targets. Initially I bought or had .308 Win. gas-guns custom-built for these competitions. I soon learned that even from bolt guns, performance past 800 yards was all over the place with the best target bullets available.

Impacts at 1000 yards were just not repeatable, and in competition against 6.5mm and 7mm rifles, we were getting smoked. I badly needed something with better performance.

As a competitor and range officer for many matches over the past 14 years, I’ve seen shooters with .308s usually end up at the bottom of the heap. Matches are won with 6mm, 6.5mm, 7mm, or .338 Lapua Magnum for the military competitions that allow that cartridge.

Trends in Long-Range Shooting

In the distant past the solution to the .308 Win.’s deficiencies was simply to up the horsepower. Many in the 1980s and 1990s went to the venerable .300 Win. Mag. to improve 1000-yard performance. Typically, they pushed a 190-grain Sierra MatchKing from a 26-inch heavy barrel. This was a true 1250-yard capable rifle/cartridge system.

The penalties are increased recoil, drastically reduced barrel life, a long action and a heavier rifle. Barrel life became an issue for the military units using the .300 Win. Mag. in their training programs.

Students could shoot out a barrel in a single course. Muzzle velocity would drop off with throat erosion, leading to reduced point of impact at distance. Shooters didn’t have a way to measure and compensate for this at the time, other than observing the POI and recording it in a log book.

There have been some significant changes in long-range shooting since then that have really increased the hit potential of shooters and their rifles.

Widespread use of chronographs, access to hand-held ballistics computers, more accurate ballistic coefficient data for our projectiles and more practical long-range competitions have really been instrumental in fundamentally transforming the long-range shooting discipline. But there has been one other major area of progress as well, and that is cartridge development.

What Makes a Good Long-Range Cartridge and Why?

In order to answer what makes a good long-range cartridge, a common approach is to look at the target and what we want to happen to it first (terminal ballistics). Then we work our way back through what happens in the air on the way to the target (external ballistics). Finally, we go into the barrel, chamber and the cartridge itself (internal ballistics).

To state the obvious, hitting the target is more important than anything else. With long-range shooting, our biggest challenge for predictable hits by far is wind deflection. The best way to deal with wind deflection is by using a projectile with a higher ballistic coefficient.

In the past, we used to focus a lot on drop at distance, which is still important. With the coming of modern laser rangefinders, what you hear more now among seasoned shooters is, “How much drift do you have at 1000 yards?”

Many articles have been written about BC, and I will simply say that BC is a value that shows a projectile’s aerodynamic efficiency. Think about an arrow versus a rock and how well they fly through the air. The arrow has a higher BC because of its sectional density and sleek aerodynamic form. By using a higher BC projectile, we don’t have to hold into the wind as much. This makes hit probability much higher, especially with wind reading errors or wind changes after the shot.

In long-range shooting, one of the first things to do is determine the range to the target. Once that is done, you know how much elevation to dial or hold, thanks to modern ballistics computers. Note the included image looking through the scope. Notice we are already dialed in for the elevation, but are holding 1.5 mils into the wind. Keep this picture in mind as we talk more about the different cartridges, as it is the most important aspect of this discussion.

Working backwards from the bullet flight in the air and into the barrel, we find that twist rate has a big influence on maximizing BC and gyroscopic stability at long-range. A general rule is a tighter twist is better for stabilizing longer, high BC bullets. A tighter twist can mean the difference of .1 to .3 mils of drift at 1000 yards, as well as less drop.

Let’s now consider case design. The biggest trend seen across most of the cases is a 30° shoulder. Think of the case as a small furnace. The more reflective the shoulder is towards the center of the powder column; the more consistent burn characteristics you will have inside the case. It’s like a log cabin fire versus a teepee.

With wind deflection, BC, twist rate and basic case design in mind, let’s look at some cartridges that have evolved long-range shooting into the 21st c century.

.260 Rem.

The .260 Rem. really started to catch on in the first decade of the 21st century, after many years as a wildcat. It is basically a .308 Win. necked down to .264”. The .260 Rem boasted, and delivered, long-range performance (wind drift and trajectory) similar to the .300 Win. Mag./190-gr. SMK combo. Supersonic reach was similar as well.

Riflemen didn’t need a completely new rifle with a long action to get true 1000-yard performance. The .260 Rem. allowed shooters to realize 1200 to 1400-yard performance with a simple barrel change on existing .308 Win rifles. It quickly became known as “the wind cheater.”

Since the .260 Remington gained SAAMI approval in 1997, its popularity has grown, particularly among long-range competitive shooters and hunters. Factory loads have been available from Black Hills with the 139-grain Lapua Scenar, CorBon’s 123- and 139-grain Lapua Scenar, Copper Creek and Prime’s 130-grain Berger VLD and Federal Gold Medal Match’s 142-grain SMK.

Now there is also Hornady’s affordable 130-grain ELD-M, which is about half the cost of most of these other loads. Applied Ballistics Munitions of Bryan Litz fame is a new entrant to the market as well. They are offering .260 Rem. loads topped with the 130-grain Berger Hybrid OTM and 140-grain Berger Hybrid Match.

I’ve been shooting .260 Rem. since 2007 and have been very pleased with its performance. Everyone was either shooting the 139-grain Scenar or 142-grain SMK when it started to gain popularity. I prefer the 130-grain Berger VLD. I think the Hornady 130-grain ELD-M factory ammo will do great things for this cartridge, as it offers a more economical option.

I have been stunned by how flat it shoots, and what little wind drift it has at 1000 yards. Biggest disadvantages of the .260 Rem. are the shoulder angle and factory ammunition costs, not counting Hornady’s new load.

Looking back at our scope picture, at 1000 yards, 59° F., at sea level. the .260 Rem. will have the following wind drift for a 10mph wind, full value (90° from the bore line) with a 1/8-inch rifling twist.

.260 Rem. factory loads
Wind Drift in Mils
123-gr. Lapua Scenar at 2950 fps 2.2
130-gr. Berger VLD at 2850 fps 2.1
130-gr. Hornady ELD-M at 2840 fps 2.1
139-gr. Scenar at 2750 fps 2.1
142-gr. SMK at 2750 fps 2.0
140-gr. Berger Hybrid at 2750 fps 1.9
140-gr. ELD-M at 2750 fps 1.8

6.5x47mm Lapua

The 6.5x47mm Lapua was designed and built from the ground up to be a dedicated precision long-range competition cartridge. Working in conjunction with the Swiss rifle manufacturer, Grünig & Elmiger, the Lapua design and engineering team developed the 6.5x47mm Lapua in 2005. Taking lessons from several other successful bench-rest cartridges, they applied them to a short 6.5mm case for very consistent performance.

They used a Small Rifle Primer to provide consistent ignition of the powder column, while increasing the base mass and pressure tolerance of the case. They also used the proven 30° shoulder of the 6mm BR, while optimizing the case volume and powder column mass.

Additionally, they incorporated the long-for-caliber neck, which helped the .222 Rem., 6mm PPC and 6mm BR to achieve their records. By using a shorter 1.843-inch case, they also supported a case-to-projectile arrangement where the bullet base is more aligned with the shoulder/neck junction. This is better for consistent projectile start movement from the case after ignition.

Using the gold standard Lapua brass metallurgy, the 6.5x47mm Lapua with SRP has a working pressure that is the highest of the three 6.5-08 class cartridges, at 63,091 psi. This allows it to generate about the same velocities as the 6.5mm Creedmoor and .260 Rem., despite having less case capacity. There are four main factory loads for this cartridge from Lapua: 120-gr. Scenar-L, 123-gr. Scenar,
136-gr. Scenar-L and 139-gr. Scenar.

6.5x47mm Lapua factory loads
Wind Drift in Mils at 1000 yards
120-gr. Scenar-L at 3026 fps 2.3
123-gr. Scenar at 2890 fps 2.2
139-gr. Scenar-L at 2816 fps 2.1
139-gr. Scenar at 2785 fps 2.1

6.5mm Creedmoor

If there is one cartridge that has made the biggest splash in the long-range shooting community in the last 10 years, it is the 6.5mm Creedmoor. This is the relatively unknown, but well-designed, Hornady .30 TC necked down to 6.5mm.

It gave Hornady a major win with an inherently accurate short 6.5mm cartridge that performs just shy of a .260 Rem. Features include a 30° shoulder, longer neck for more consistent neck tension and optimum projectile base placement at the shoulder/neck junction. The 6.5mm Creedmoor has quickly become a favorite among long-range shooters.

At this year’s SHOT Show, there seemed to be a new wave of 6.5mm Creedmoor rifles and ammunition poised to take the market by storm. This included Lapua brass, Federal’s Gold Medal Match 130-gr. Berger Hybrid and 140-gr. OTM loads, Hornady’s 140-gr. ELD-M, 143-gr. ELD-X, 147-gr. ELD-M, Winchester’s 140-gr. HPBT, Nosler’s 129-gr. Accubond Long Range and 140-gr. BTHP ammo and a laundry list of major rifle manufacturers finally jumping on board the 6.5mm Creedmoor train. From everything I’m seeing, the 6.5 Creedmoor has become the new go-to long-range rifle standard.

6.5mm Creedmoor factory loads
Wind Drift at 1000 yards in Mils
129-gr. SST Superformance at 2950 fps 2.4
129-gr. Nosler Accubond Long Range at 2850 fps 2.1
130-gr. Berger Hybrid OTM FGMM at 2875 fps 2.0
140-gr. Federal OTM at 2700 fps 2.2
140-gr. ELD-M at 2710 fps 1.8
143-gr. ELD-X Precision Hunter at 2700 fps 1.9
147-gr. ELD-M at 2695 fps 1.7

6mm Creedmoor

The 6mm Creedmoor is another cartridge from Hornady that is becoming more and more popular in the Precision Rifle Series long-range competitive discipline. Hornady has recently added both factory ammunition and brass for it. It is currently undergoing SAAMI standardization with the full weight of Hornady behind it. Hornady saw that a lot of PRS competitors were necking 6.5mm Creedmoor down to 6mm for a flatter-shooting, low recoil solution for PRS. They then decided to make it a factory offering.

Using the same accuracy and efficiency recipe for case design as most of these modern long-range cartridges, the 6mm Creedmoor retains the 30° shoulder and long-for-caliber neck. Ignition is by a Large Rifle Primer.

One important performance characteristic of 6mm cartridges is reduced sight movement due to the lower recoil. So it is much easier for the competitor to see impacts or misses, and gain valuable wind data from those shots.

Hornady currently lists one factory load for this cartridge, the 108-gr. ELD Match, at 2960 fps from a 24-inch barrel. Copper Creek lists three different loads using: Hornady’s 105-gr. BTHP, Berger’s 105-gr. Hybrid and DTAC’s 115-gr. RBT.

6mm Creedmoor
Wind Drift at 1000 yards in Mils
105-gr. BTHP at 3050 fps 2.2
105-gr. Berger Hybrid at 3050 fps 1.9
108-gr. ELD-M at 2960 fps 2.1
115-gr. DTAC RBT at 2950 fps 1.7

Reviving the .300 Win. Mag.

Along with the developments of all these newer cartridges and projectiles, experimenters have worked to improve the effective range
and performance of the hard-hitting .300 Win. Mag. The drivers have been the U.S. military and shooters who like what we call Extreme Long Range (ELR), which covers distances from 1,000 yards on out.

While all of our allies and coalition partners have adopted the .338 Lapua Mag. for their long-range bolt-action sniper systems, the U.S. military decided to stick with the .300 Win Mag. This was despite many senior influential weapons procurement people within the U.S. sniping community who were strong advocates of the
.338 Lapua.

Either way, projectile developments have enabled the .300 Win. Mag. to bark and actually bite at the heels of the .338, extending the effective range of the system measurably.

.300 Win Mag factory loads
Wind Drift 1000 YARDS IN Mils
Supersonic Reach @ Sea Level
190-gr. SMK at 2950 fps 2.1 1300 yds
200-gr. Hornady ELD-X at 2860 fps 1.9 1300 yds
195-gr. Hornady BTHP at 2930 fps 1.8 1350 yds
185-gr. Berger Juggernaut at 3090 fps 1.8 1450 yds
215-gr. Berger Hybrid TGT at 2886 fps 1.5 1675 yds

Conclusions

As we stand in 2017, the world of long-range cartridges is more than alive and well. We have gone from the 20th century, where the limitations of the .308 Win and .300 Win. Mag. spurred on a new era of cartridge and projectile development. The results have extended the effective range of short action rifles considerably.

It has also seeded the market with substantial advancements in ballistics computing prediction capability for the common shooter, and opening up several different disciplines in practical long-range shooting.

We have seen the 6.5-08 class of cartridges become very popular in the past two decades. Now 6mm variants are gaining traction, flagshipped by Hornady’s 6mm Creedmoor. We have also seen the old .300 Win. Mag. extend its reach, proving it is still relevant in the 21st century.

The .308 Win. will continue to be a popular long-range cartridge, especially with modern bullets and ballistics computers. But a new selection of long-range cartridges is setting the standard for the future.

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