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The .30-378 Versus The 7mm STW

Both cartridges kick ballistic butt, but we pick Remington’s new Westerner over Weatherby’s big-dog chambering.

The .30-378 Weatherby (right) and 7mm Shooting Times Westerner (left) were developed for long- range shooting across beanfields and canyons. They overpower such cartridges as the .30-06 Springfield (center) in case capacity, velocity, and energy delivered to the target.

A couple of calibers introduced for 1997 may well be the best long-range big-game cartridges ever made in America. Remington and Weatherby have legitimized two popular wildcats, and in doing so they have redefined the parameters of flat trajectories and long-range energy delivery. With these companies making “honest cartridges” out of the .30-378 Weatherby and the 7mm Shooting Times Westerner, long-range shooting has been elevated to a higher level.

We recently tested rifles chambered for these new cartridges—to assess the quality of the rifle products that fire these hot new loads and to compare the ballistic performance of the rounds themselves. What we found pleased us in many ways, for both rounds are solid complements to the existing factory-cartridge menus offered by Remington and Weatherby.

Weatherby .30-378:
The Big Dog

Unquestionably, the .30-378 is the big dog of midline rifle cartridges. Ever since the movie Tin Cup repopularized the expression “Let the big dog eat”—meaning the most powerful members of a group get first crack at the goodies—we’ve thought the phrase described this cartridge perfectly. Its huge case has the ability to hold well over 120 grains of powder, and that is a hearty appetite.

This cartridge is formed when the massive .378 Weatherby parent cartridge is necked down to .30 caliber, maintaining the trademark Weatherby double-radius shoulder. The .30-378 was developed for 1,000-yard benchrest shooting, but it has its place as an ultra long-range deer cartridge. It has also proven itself as a long-range elk round; with the proper bullets, it is capable of taking any game on the North American continent.

We first encountered the .30-378 back in 1984 in an Ungava caribou camp along the George River. The hunter who was lugging it claimed the 180-grain bullet ran at 4,000 fps. He determined this velocity figure by the unscientific method of shooting at a distant rock with the rifle and a .220 Swift in succession. It was generally agreed that the bullets from the two guns took the same amount of time to hit the rock. Since the Swift exceeds 4,000 fps, he judged that the .30-378 did as well.

Today’s reality is something else. Weatherby still has not shipped factory ammo, and so we cannot prove or disprove the company’s claim of 3,450 fps with a Barnes 180-grain X-Bullet. But knowing that the company’s technicians are experimenting with powders and blends of powders that are not available to the reloader, that velocity is achievable, in our estimation.

We want to stress that we are exploring new territory here and that our testing is far from over. However, we have tested most of the popular powders and bullets for this cartridge and have not achieved the results we had hoped for and that others have claimed. As any reloader knows, this situation can change overnight as new powder or even powder lots become available.

Still, after experimenting with a variety of powders currently available to the handloader, we have found no truly safe handload that can deliver that velocity with that bullet. Though there are some wild claims of 3,600 fps or even 3,700 fps being made about this cartridge/bullet combo, we would have to see it to be convinced. Most of the loads we built that approached the factory velocity left the gun’s bolt difficult to open. Those that exceeded 3,500 fps were dangerously over pressure, and we wouldn’t attempt 3,700 fps even on a bet. In our Weatherby Accumark rifle the most velocity we could safely achieve has been 3,300 to 3,350 fps, which still ain’t too shabby.

At this point in time we have found that our rifle produced far different results than what has been reported in other gun magazines. Part of that no doubt is due to the difference in rifles. Much of the previously published data was developed in custom rifles built for the caliber before Weatherby brought it out as a factory item. Differences in lead and throats may make much of this data suspect and unacceptable for factory-chambered rifles. Also notable is that loads which showed no pressure signs in our rifle when tested in 20-degree weather last winter (also showing velocities below 3,300 fps) were much too hot when shooting in 70-degree temperatures. This should be considered when working up hunting loads.

Based on our testing, we believe those shooters who are thinking that they can buy a .30-378 to load with light bullets and propel them at ultra-fast velocities for deer and antelope are probably going to be disappointed. In our view, it will be difficult to get top velocities in guns with barrels shorter than 30 inches. You will also burn a lot more powder and suffer more recoil to do it.

However, this cartridge starts to come into its own with bullets heavier than 180 grains, particularly 200-grain bullets. We have a handload that uses H870 powder and a 200-grain Nosler Partition bullet. With a muzzle velocity of 3,230 fps it averages 0.75 inch at 100 yards for three shots. Last December it proved devastating on a nice Alabama whitetail buck.

Because both calibers will be initially offered in one factory load, our comparison for now will center on the factory loads for each caliber. In light of that we will use the velocity figure provided by Weatherby of 3,450 fps with a 180 grain X-Bullet.

Remington 7mm Shooting Times Westerner
Gun writer Layne Simpson created the 7mm Shooting Times Westerner cartridge in 1989 and named it for his employer, Shooting Times Magazine. The Westerner moniker comes from its expected use as a long-range cartridge, as opposed to the less popular 7mm Shooting Times Easterner based on the .307 Winchester cartridge.

The 7mm STW uses a parent case of the 8mm Remington Magnum, which, of course, is necked down to 7mm and its case taper straightened slightly. The new round has become very popular very quickly among long-range deer hunters.

“We kept watching the sales of 8mm Remington Magnum brass climb up and up,” said a Remington ammo-development specialist. “We knew from gun sales that that it wasn’t being used in rifles chambered for that caliber. and it became apparent that the popularity of the 7mm STW was just too big to ignore any longer.” Once these trends were clear, Remington legitimized the popular then-wildcat round.

Initial factory loads feature a 140-grain bullet with an advertised muzzle velocity of 3,325 fps. I found that my rifle’s 25.5-inch barrel actually exceeded that, averaging 3,359 fps. Handloads should be able to boost this velocity by a considerable margin. Some reports have 140-grain bullets running over 3,500 fps, but like the .30-378’s published figures, we withhold judgment about whether those speeds are achievable with mainstream loads.

Based on our experience with the round, we think that the 160-grain bullet will be more practical for this cartridge. Indeed, the Barnes #1 Reloading Manual shows several loads that exceed 3,300 fps using this bullet. Also, Remington will likely bring out more factory loads soon. With the current factory loads, the 7mm Westerner has an 11-percent energy gain over the 7mm Remington Magnum and a 7.1-percent gain over the 7mm Weatherby Magnum at 400 yards.

How Do They Compare?
Using the two factory loads and an 8-inch deer-kill zone, we calculated the .30-378 Weatherby’s point-blank range to be 381 yards (point-blank range is the distance at which the round’s rising trajectory and falling trajectory don’t vary more than 4 inches from the point of aim). The 7mm STW has a point-blank range of 359 yards, or 22 yards less. When sighted dead on at 200 yards, the .30-378 is 0.9 inches high at 100 yards, 4.65 inches low at 300 yards, 13.56 inches low at 400 yards and 27.33 inches low at 500 yards. The 7mm STW, on the other hand, when sighted dead on at 200 yards is 1.07 inches high at 100 yards, 5.36 inches low at 300 yards, 15.82 inches low at 400 yards and 32.38 inches low at 500 yards.

The .30-378 delivers 3,243 ft-lbs of energy at 100 yards, 3,046 ft-lbs at 200 yards, 2,858 ft-lbs at 300 (about what the .30-06 has at the muzzle), 2,677 ft-lbs at 400 yards and 2,504 ft-lbs at 500 yards. The 7 mm STW has 3,096 ft-lbs of energy at 100 yards, 2,848 ft-lbs at 200 yards, 2,613 ft-lbs at 300, 2,390 ft-lbs at 400 yards and 2,178 ft-lbs at 500 yards.

Notice that at 200 yards the .30-378 has as much energy as the 7mm STW does at 100 yards. By 500 yards the difference is even more pronounced as the big Weatherby has more 114 more ft-lbs than the 7 mm has at 400 yards.

This is also evidenced in that the Weatherby has 2.26 inches less drop at 400 yards (with a 200-yard zero) than the 7mm and at 500 yards the difference is more than 5 inches. This seems insignificant until you consider that the average kill zone on a pronghorn antelope is not a lot larger. Five inches can cause a miss or wounding loss on any game, especially at long ranges.

Performance Shooter Recommends
Unquestionably, the .30-378 is the performance champ in this test. It simply shoots flatter and hits harder than its competitor with factory rounds. As an cartridge used to kill elk, moose, or other bigger game, then the Weatherby Accumark .30-378 gets the nod. In its weight class, the .30-378 is the baddest boy around, and that has its appeal. In terms of sheer performance our vote goes to the Weatherby. We do have reservations about the Weatherby Accumark .30-378 package, however. With a suggested retail of $1,427 for the rifle and $85 a box for the ammo—that’s not a misprint—we have to wonder if the Weatherby is worth it.

The suggested retail for the Remington BDL is $789, or $879 for the Sendero. Remington says it doesn’t offer a suggested retail price for the round, but a company spokesman said a box will sell for around $33.50, depending on the individual retail shop’s markup.

Thus, when measured in terms of bang for the buck, we don’t think the slight performance penalty the Remington 7mm STW factory round suffers really matters for hunting deer, antelope, or other midsize big game, the pursuits for which most of these rifles will be used. Moreover, with the right handloads, we believe the 7mm STW could take any game on the North American continent except big bears. No hunter needs this kind of power to kill a deer at any reasonable shooting distance, but driving hunting-weight bullets to flat trajectories requires high velocities and resulting high energy levels.

Of these two new cartridges, we think the 7mm STW is a more flexible, more affordable field choice than the Weatherby chambering.

 

-By Dr. George E.

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