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Compared: Popular and Useful .270 and 7mm Rifle Cartridges (.270 Win., .270 WSM, 7mm-08 Rem., .280 Rem., 7mm Rem. Mag.) By Gary Zinn  While doing research for the article Practical Performance of Popular Rifle Cartridges, I became interested in taking a closer look at cartridges in the closely related .277 and .284 (7mm) bore sizes. Two things motivated this interest. The first was that four of the eighteen cartridges I covered in the Practical Performance article were in these calibers, which were exceeded only by the five cartridges in .308 caliber. Second, it occurred to me that two cartridges in particular make the .277 and 7mm calibers important; these are the .270 Winchester and 7mm Remington Magnum. That the .270 Winchester and 7mm Remington Magnum are popular and useful cartridges is evidenced by the fact that they rank fifth and seventh, respectively, on the latest 10 Best Selling Centerfire Cartridges in the USA list. In addition, the 7mm-08 Remington cartridge made honorable mention on the 10 Best list and in the Practical Performance article I added the .280 Remington (not extremely popular, but useful). With these four cartridges in front of me, the only remaining question was, "Are there any other cartridges in these bore sizes that are popular and/or useful?" Pondering this question and doing some research led me to the conclusion that there was one more cartridge that merits inclusion, the .270 Winchester Short Magnum (WSM). Overview of rifle and factory ammunition availability Here are some indicative data that give a sense of the availability of rifles and ammo options in each of these cartridges. I used the Able Ammo internet list of in-stock rifles to tally the rifle availability summary, and the MidwayUSA in-stock ammo listings to get an indication of the number and bullet weight ranges of available cartridges. All data were collected in late 2016. Able Ammo lists bolt action rifles in 7mm-08 Remington from 11 commercial rifle makers, with multiple models offered by some. In addition, the Browning BAR (autoloading) and BLR (lever action) rifles are chambered in 7mm-08. MidwayUSA lists 23 7mm-08 factory loads in ten brands, with bullet weights ranging from 120 to 156 grains. The .270 Winchester is so popular that virtually everyone makes rifles chambered in the caliber. I tallied 18 bolt action makes, plus the Browning BAR, Browning BLR, Remington 750 (autoloading) and Remington 7600 (pump) rifles. 44 factory loads are available in 15 brands, in bullet weights from 120 to 150 grains. The .280 Remington is the cartridge with the thinnest selection of both rifles and ammo. Five brands of production rifles are offered, all bolt actions. 17 loads are available in eight brands, in 125 to 165 grain bullet weights. The .270 WSM has a better situation than the .280 in rifle availability, with eight brands of bolt action rifles listed, plus the Browning BAR and BLR rifles. 19 loads are available in eight brands, in 120 to 150 grains bullet weight range. Finally, the 7mm Remington Magnum is so well regarded that rifle and ammo availability approaches that of the .270 Winchester. 13 makes of bolt action action rifles are offered in the chambering, plus the Browning BAR and BLR. 12 ammo makers do their part by making 43 loads in the 139 to 180 grain bullet weight range. Performance of selected loads in each cartridge To evaluate performance of the cartridges, I chose a single "workhorse" Federal Premium brand commercial load in each non-magnum cartridge. I chose two loads, one each with a relatively light and heavy bullet, for the two magnum cartridges. The selected hunting bullets are listed below, with the muzzle velocity (MV), ballistic coefficient (BC) and sectional density (SD) of each bullet.
I should note two things before commenting briefly on each of the loads listed. First, I did not include muzzle energy values for these loads because they all are quite strong (ranging from just over 2400 ft. lbs. to about 3100 ft. lbs.) and so have no particular significance in understanding the performance of the cartridges. Retained energy downrange is significant and will be discussed later. All MV values shown above are for 24" barrels. This is good in that it facilitates direct comparisons of load velocities. However, the non-magnum cartridges will normally be chambered in 22" barrels, the 7mm Rem. Mag. and .300 Win. Mag. mostly come in rifles with 24" barrels and the .270 WSM comes in a mixed bag of 22", 23", and 24" barrels. MV and downrange performance will be reduced with barrels shorter than 24". I feel that 140 grain bullets are the best choice for non-magnum 7mm cartridges and that lead core jacketed bullets (Remington Core-Lokt, Sierra Pro-Hunter, etc.) or polymer tipped (Hornady SST, Nosler Ballistic Tip, etc.) bullets are great choices for deer and other Class 2 game. The loads I selected to evaluate the 7mm-08 and .280 reflect that opinion. The performance of the .270 Winchester with a 130 grain bullet is what made the cartridge a legend. Accordingly, I chose the 130 grain Nosler Ballistic Tip bullet to evaluate this cartridge, again with Class 2 game in mind. I chose two loads for the .270 WSM and 7mm Remington Magnum to explore what these cartridges can do against both Class 2 and Class 3 game. For Class 2 use, I chose the same bullet weights as I did for the .270 and 7mm non-magnum cartridges. However, I chose robust Federal Trophy Bonded Tip bullets for these loads. Because the magnums drive these bullets at very high velocities, I believe that they would perform more dependably at short to intermediate range impacts than would conventional jacketed lead core or polymer tipped bullets. Bonded bullets, such as the Trophy Bonded Tip, Hornady InterBond, etc., would be less likely to come apart at impact with, say, shoulder bones than would the more conventional bullets. I selected the proven Nosler Partition bullet for use on Class 3 game, with bullet weights of 150 grains in the .270 WSM and 160 grains in the 7mm Rem Mag. The Nosler Partition, Swift A-Frame and Trophy Bonded Bear Claw are three examples of the type of very sturdy bullets that are recommended for large, tough and sometimes mean critters. Such bullets are designed for deep penetration, consistent expansion and little if any core separation when shot into large animals. These bullet designs and weights are arguably the best choices for the .270 and 7mm magnums for elk and other Class 3 game. The sectional densities of the loads are noted above. Chuck Hawks explains the importance of SD in The Sectional Density of Rifle Bullets. The bottom line is that the SD of a hunting bullet (of given expansion characteristics) is the best basic indicator of its penetration ability and Chuck offers the guideline that small bore (under .33 caliber) bullets for Class 2 game should generally have a SD of .215 or better, while .26 or higher is desirable for Class 3 game. Therefore, the 130 grain .270 and 140 grain 7mm bullets, with SDs of .242 and .248 respectively, are more than adequate for common Class 2 game, such as deer. The 150 grain .277 (SD .279) and 160 grain 7mm (SD .283) bullets are fully capable for hunting Class 3 game, such as elk. So far, all we have done is shop for rifles and considered bullet weights and types suitable for different hunting situations. Now, it is time to examine the external ballistics and realistic capabilities of these cartridges. The list below shows the +/- 3" maximum point blank range (MPBR), retained energy (RE), and the far zero (FZ) of each load featured in this article. (MPBR and FZ are rounded to the nearest five yard increment, RE is at the rounded MPBR.) These data will be the basis for evaluating the performance of each load for hunting.
It is no surprise that the 7mm-08 has the most modest external ballistics of the five cartridges. However, it is not a weakling, with a MPBR of 280 yards and 1637 ft. lbs. of bullet energy at this distance. This is downrange performance that nestles comfortably between the .260 Remington and .308 Winchester. The 7mm-08, like those two cartridges, is a very capable tool for hunting all Class 2 game at extended ranges. The 7mm-08 was commercialized by Remington in 1980 and did not garner the hype lavished on many new cartridges. The cartridge pretty much flew under the radar for years, with a few rifles and loads offered and an occasional mention in the shooting and hunting media. Meanwhile, shooters must have caught onto a good thing, because now the 7mm-08 is positioned just outside the Top 10 among popular cartridges. That this cartridge has increased in popularity this much, without a great deal of hype or promotion, suggests to me that it will be viable for a long time to come. Dimensionally, all that separates the .270 Winchester and .280 Remington cartridges is the .007" difference in bore diameter, plus the .280 has a .051" longer case body (and consequently one percent greater powder capacity) to prevent .280 cartridges being accidentally fired in .270 rifles. The two cartridges look virtually identical and their performance is interchangeable. The differences between the two cartridges are so small that they do not justify the many arguments, in print and around hunting campfires, over which cartridge is better. The ballistics data for the factory loads I chose to evaluate these two cartridges inadvertently show how equivalent they are in a slightly different way. The .280 drives a 140 grain bullet over virtually the same trajectory as that of a 130 grain .270 bullet. The only noticeable difference is that the .280 has 149 ft. lbs. greater retained energy at 295 - 300 yards. I doubt that a deer hit in the vitals with a bullet in either caliber at that range would notice the difference. (Switch to a 140 grain bullet in the .270 and that advantage disappears. -Editor.) The .270 Win. was introduced in 1925 and it has become very popular. For a couple of decades it was the flattest shooting big game cartridge loaded in North America and it remains the standard of comparison for long range cartridges. (The enthusiastic endorsement of Jack O'Connor doubtless helped this process along.) I began hunting deer in 1957, as a teenager, which was, coincidentally, the year the .280 Rem was introduced. Remington designed the .280 to compete with the .270 Winchester, but loaded it to slightly lower pressure for use in their autoloading Model 742 and pump action Model 760 rifles. This made the .280 slightly inferior to the performance of the .270. I clearly recall the .270 was viewed as the ultimate deer cartridge by hunters I knew in my teen years. I also recall that the .280 was somewhat derisively called a ".270 wannabe" by many hunters and even some gun writers. The point is that the .280 never had a chance to overtake the .270 in reputation and popularity. Today, the .270 sits in fifth place on the Top 10 list, while the .280 survives largely because it has a small, faithful clientele that prefer it, for whatever reasons. The comparison of these two cartridges boils down to this: Anyone who has a rifle chambered in either .270 Winchester or .280 Remington has no practical need to own the other. Winchester launched its family of short magnum cartridges with the .300 WSM in 2001. Within a year, the .270 WSM and 7mm WSM cartridges were introduced, followed by the .325 WSM in 2005. The .300 WSM has been quite successful and .270 WSM reasonably so, while the 7mm and .325 WSMs never caught on in the marketplace and today they languish on life support. Before the .270 WSM, the most notable cartridge with performance exceeding that of the .270 Winchester, in the .277 bore size, was the .270 Weatherby Magnum. I believe that the .270 WSM has been successful because it performs at a level somewhat above that of the .270 Winchester (when fired from a 24" barrel), although it falls well short of the .270 Weatherby. Summarizing the comparative performance of the .270 Winchester and .270 WSM begins with the MV of same weight bullets. For the loads listed above, the .270 WSM drives a 130 grain bullet at a MV 7.2% greater (3280 vs. 3060 f.p.s.) than the .270 Win. Downrange, this translates into a 6.7% longer MPBR (320 vs. 300 yds.) for the .270 WSM. For long hunting shots, the .270 WSM has 13.7% more retained energy (1930 vs. 1698 ft. lbs.) at MPBR than the .270 Win. Finally, the far zero of the .270 WSM is 5.9% further (270 vs. 255 yds.) than the .270 Win. These performance advantages for the .270 WSM in Class 2 game bullet weights, such as the 130 grain .277 bullet, may be enough to justify preference for the .270 WSM over the .270 Winchester in the minds of some hunters. Personally, I would not choose the WSM over the .270 Win based on the performance of 130 grain bullets alone. Rather, if one had to choose only one .277 caliber cartridge, I believe that what works in favor of the .270 WSM is what it can do with heavier bullets. I chose a heavy .270 WSM load with a 150 grain bullet for this article. I could compare its performance with that of a 150 grain bullet load in the .270 Win, but that would be setting up the latter cartridge as a straw man. The WSM load would beat the .270 Win load even worse than was the case when the 130 grain loads were compared. What is more interesting (and I did not see coming) is how the 150 grain .270 WSM load compares with the 140 and 160 grain loads for the 7mm Remington Magnum. To review, here are the key ballistics for the three loads.
Once I had done the math, I was surprised at how well the 150 grain .270 WSM load kept pace with the two 7mm Rem. Mag. loads. For MV, the WSM load was just 10 f.p.s. slower than the 140 grain 7mm load and 150 f.p.s. (5.1%) faster than the 160 grain 7mm load. MPBR for the WSM was the same as that of the 140 grain 7mm load and 15 yards longer than the 160 grain 7mm load. Far Zero for the WSM load and the 140 grain 7mm load is identical, while FZ of the heavy WSM load is 10 yards longer than the 160 grain 7mm. Perhaps the most surprising comparative result was that the 150 grain .270 WSM load carries more energy downrange than either of the 7mm Rem Mag loads. The WSM load has 10.5% (197 ft. lbs.) more RE at MPBR than the 140 grain 7mm load and 25 ft. lbs. more than the 160 grain 7mm load. These numbers are what they are, but do not make too much of them. If one hits a game animal in the vitals with a bullet carrying roughly a ton of kinetic energy at 300 yards the quarry is going to be dead, whether the bullet hits with a few percentage points more or less ft. lbs. of energy. What I conclude from all this is that the .270 WSM, firing full power loads with 150 grain bullets, has performance comparable with that of loads with 140 to 160 grain bullets in 7mm Rem Mag. As I said, I did not see this coming before I crunched the numbers. (However, compare both calibers with 150 grain bullets and the 7mm Rem. Mag. is superior at all ranges. -Editor.) Be aware, though, that 150 grain bullets are the maximum weight generally loaded in the .270 WSM and other .27 bore cartridges, while the 7mm Rem Mag can fire hunting bullets weighing up to 175 grains. Just for kicks, I nosed around on the reloading websites to see what the 7mm Rem. Mag. could do with such bullets. The Nosler load data site gave me something to think about. Nosler makes its classic Partition and high tech AccuBond Long Range bullets in the 175 grain, 7mm size. The SD of these bullets is .310 and they have BCs of .519 and .672, respectively. Nosler lists 7mm Rem. Mag. load recipes for nine powders using these bullets. The highest MV of all loads and most accurate load tested used 62.5 grains of RL22 powder. Using the higher BC AccuBond Long Range bullet, this load generated MV of 2970 f.p.s. from a 24" test barrel, with muzzle energy of 3427 ft. lbs. Downrange, the MPBR would be 300 yards, with 2546 ft. lbs. of retained energy. The far zero would be 255 yards. I am impressed! In summary, the .270 WSM and 7mm Rem. Magnum, using bullets on the heavy side for their respective bore sizes, are potent against Class 3 game. I would not advocate going after the biggest and baddest Class 3 animals with 150 grain bullets in the .270 WSM, but a 7mm Rem Mag, loaded with premium 175 grain bonded or partitioned hunting bullets, seems fully adequate for anything that a sane person would hunt with a small bore cartridge. Other considerations There are three other topics I want to briefly discuss. These are using far zero as a shooting distance limitation guide, recoil of the selected cartridge loads and reloading considerations. I am not buying into the current fad that promotes extremely long range hunting shots. Simply put, I feel that this is irresponsible hunting behavior. I personally do not even use maximum point blank range as a shooting distance limitation, although I sight my hunting rifles in for a +/- 3" MPBR. Rather, I use the far zero (FZ) associated with the MPBR of a particular cartridge and load as my distance limit for my deer rifles. This gives me a margin of error in case I underestimate shooting distance in the field. To illustrate, assume I hunt with a 7mm-08 Remington rifle, using the 140 grain load featured in this article. The MPBR of this load is 280 yards and the FZ is 235 yards. If I sight in the rifle for the MPBR of 280 yards, but limit my hunting shots to the FZ of 235 yards, then I have a 45 yard cushion in case I underestimate the range to my target. Put another way, suppose that I have a shot opportunity at a deer that I visually estimate to be about 230 yards away. If I execute the shot properly, I will still get a vital zone hit even if I have underestimated the range by some 50 yards, since the bullet trajectory will still be within the MPBR of 280 yards. I explain the concept of using FZ as a shooting distance limitation more fully in Practical Performance of Popular Rifle Cartridges. For the cartridges and loads featured in this article, the MPBR / FZ data sets range from a low of 280 / 235 yards for the 7mm-08 cartridge and load to a high of 320 / 270 yards for the .270 WSM with the 130 grain bullet. Altogether, the five cartridges and seven loads featured in this article have an average MPBR of 295 yards and an average FZ of 255 yards. This means that the average range underestimation cushion is 40 yards. In my world, 250 yards is a long hunting shot and having a range underestimation cushion of 40 yards is both a comfort and a confidence builder. Recoil Recoil is the price to be paid for the high performance of the hotter cartridges and loads I have covered. To quantify and compare the recoil of these loads, I assumed a uniform field-ready rifle weight of 8.5 pounds (7.0 pound bare rifle plus 1.5 pounds for scope, sling and cartridge load). I did not have information on the powder charge of each factory load, so I consulted a couple of reloading data manuals to find powder charges that would drive bullets of given weights at velocities very close to the factory load velocities. Here is a tally of the results when I entered the relevant data into a recoil calculation program.
The results were pretty much as I expected. The most startling result is that the .270 WSM kicks so hard. This cartridge burns a lot of powder to get its high velocity and flat trajectory. Everything has a cost. The 7mm-08 has a very mild recoil, the .280 Rem and .270 Win generate recoil levels that one would expect from high performance non-magnum cartridges and the two magnums get into the low end of the serious recoil range. Reloading considerations All five cartridges are eminently reloadable. The number of powders that work well with each cartridge has never been larger and the selection of .277 and 7mm hunting bullets is great in terms of brands, weights and types. I checked a couple of my go-to reloading components websites and the only yellow flag I found was that there are currently only four brands of .270 WSM brass on the market, two of which (Norma and Nosler) are quite pricey, at over $2 per case. Brand options and prices of brass for the other four cartridges are better. Conclusion Three of these cartridges already have complimentary labels. Chuck Hawks has called the .270 Winchester "great" and the 7mm-08 Remington "sensible." I have previously expressed the opinion that the 7mm Remington Magnum is the best rifle cartridge that Remington has ever introduced. The .270 WSM adds a capable, but not overblown, magnum chambering in .27 caliber, while the .280 Remington is ballistically interchangeable with the .270 Winchester. It seems to me that these five cartridges, among them, offer pretty much anything a hunter could wish for in the .27 and .28 bore sizes. Note: Full length articles about all of the cartridges mentioned in this article can be found on the Rifle Cartridges index page. |
