The 7mm-08 Remington: A Worthy Successor to the 7x57mm Mauser Cartridge
By Gary Zinn
For almost 40 years I have been having an off-and-on romance with a sweet little cartridge known as the 7x57, the 7mm Mauser, and the 7mm Spanish Mauser. There is nothing spectacular about the 7x57. Yet I think I have seen more game killed with fewer shots from this modest little cartridge than with any other."
These words were written by Jack O'Connor, the Dean of American Gun Writers, in 1972. The article in which they appeared was published in the 1974 Gun Digest under the title "Forty Years with the Little 7mm."
JOC summarized why the 7x57 is so effective as follows:
"The explanation for its deadly efficiency does not lie in blinding velocity, in big bullets, in a frightening number of foot pounds of energy. It lies in the light recoil, coupled with the excellent hunting accuracy of so many 7x57s. Those who use it are not afraid of it and, as a consequence, they tend to shoot it well and to place their shots well. In case no one has told you, the most important factor in killing power is putting that bullet in the right spot."
The 7x57mm was developed in 1892 at the Mauser Werke in Germany and was quickly adopted by Spain (and eventually by several other countries) as a military cartridge. It became popular as a sporting cartridge in England (as the .275 Rigby), Europe and Africa. JOC notes that the popularity of the cartridge in the U.S.A. was an off and on thing, with a muddled history of American cartridge makers offering and then dropping 7x57 hunting loads and domestic rifle makers sporadically offering rifles chambered in 7x57. (O'Connor mentions Remington and Winchester as offering 7x57 rifles mostly before WW II and Ruger in the early 1970s.) CZ USA also offered its Model 550 American in 7x57 for a time.
At present (2017), the American hunter who yearns for a new rifle chambered in 7x57mm will have to take some pains to get it. I cannot identify any major American rifle maker that is regularly offering rifles in 7x57, although a few American specialty makers (Cooper, E.R. Shaw, Jarrett, Nosler) and some European rifles (Blaser, Purdey, Rigby, etc.) are chambered for the cartridge. The Ruger No. 1 single shot rifle is currently available in .275 Rigby (7x57mm) as a Lipsey's distributor exclusive. The alternatives are to have a 30-06 or equivalent action rebarreled to 7x57, or have a custom rifle built.
However, there is a commonly available, commercial rifle cartridge that offers similar ballistics: the 7mm-08 Remington. I had no trouble finding commercial rifle companies that offer one or more models chambered in 7mm-08, including such widely distributed brands as Browning, CVA, Howa, Kimber, Mossberg, Remington, Ruger, Sako, Savage, Thompson/Center, Tikka, Weatherby and Winchester. Most of these are bolt action guns, plus Browning chambers its autoloading BAR and lever action BLR in the caliber.
Similarly, commercial ammunition choices are broader for the 7mm-08 than for the 7x57mm. For example, MidwayUSA lists 31 7mm-08 loads, but only 12 for the 7x57mm.
The 7mm-08 Remington in a nutshell
The 7mm-08 Remington is simply the .308 Winchester cartridge necked-down to handle .284 inch diameter bullets. Commercialized in 1980, the 7mm-08 did not garner the hype lavished on many new cartridges. It 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 rates an honorable mention on the latest 10 Best Selling Centerfire Cartridges in the USA list, while the selection of commercial loads has expanded.
The 7mm-08 cartridge features two modest enhancements compared to the 7x57 Mauser. First, the 7mm-08 has a maximum C.O.L. of 2.800 inches, so it fits in standard short (.308 Winchester length) actions. The 7x57 cartridge, with a maximum C.O.L. of 3.065 inches, must be used in longer (usually .30-06 length) actions.
Second, the 7mm-08 Remington, although it has somewhat less case capacity, is rated to work at a higher SAAMI maximum average pressure (61,000 psi) than the 7x57mm Mauser (51,000 psi), which is commercially loaded at the lower pressure in deference to ancient Model 1893 Spanish Mauser rifles. This means that the 7mm-08 will generally drive bullets of any particular weight at somewhat higher velocity than will a 7x57. (Of course, in any modern action, from the 1898 Mauser forward, the 7x57 can be loaded to the same MAP as the 7mm-08 and achieve the same ballistic performance. -Editor)
The Nosler Load Data website lists the useable case capacity of the 7x57mm cartridge as 52.5 grains of water, with a 140 grain bullet properly seated. The comparable capacity of the 7mm-08 cartridge is 48.6 grains of water.
The Hodgdon Reloading Data Center provides an apples to apples comparison of velocities and pressures between the cartridges. A 40.5 grain charge of IMR 4064 powder will drive a 140 grain bullet at a muzzle velocity (MV) of 2615 fps from a 7x57mm rifle with a 24 inch barrel, generating a pressure of 45,600 CUP. The 7mm-08, loaded with the same powder and charge weight, generates 50,300 CUP of pressure and will drive the same bullet at 2770 fps MV from a 24 inch barrel. Results will vary with different powders, bullet weights and barrel lengths, of course. (See The Sensible 7mm-08 Remington for more information.)
Performance of the 7mm-08 Remington
Available hunting bullets in 7mm caliber (.284 inch) range from 110 to 175 grains in weight, while current factory loaded ammunition choices include 120 through 160 grain bullets. Loads with 139 or 140 grain bullets are the most common. I selected representative factory loads with 120, 139 and 150 grain bullets to illustrate the performance of the cartridge. Also, I selected a reload that I felt represented the performance of the 175 grain bullet.
I adjusted/estimated the stated muzzle velocity for each load to a 22 inch barrel length and calculated the +/- 3 inch (6 inch target diameter) maximum point blank range (MPBR) and far zero (Zero) of each load. I then calculated the 100 yard Hornady H.I.T.S. (HITS) score for each load, along with the G&S Online Killing Power Score (KPS) at 100 yards. Finally, I estimated the recoil of each load (assuming an 8.0 pound rifle weight) and noted the sectional density of each bullet. Following are the results.
(Data used for the KPS and recoil comparisons mentioned below are from the G&S Online Rifle Cartridge Killing Power Comparison and Rifle Recoil Table, respectively. These may be found on the Tables, Charts, and Lists index page of the Guns and Shooting Online website.)
Federal Fusion 120 gr. JSP-BT: MV 2960 fps, SD .213, Zero at 240 yards, MPBR 280 yards, 100 yard HITS = 686, KPS = 25.9, Recoil = 12.8 ft. lbs.
The HITS scores of this load places it solidly in the Hornady medium game category (HITS scores 501 - 900 are recommended for 50 to 300 pound game animals). This weight range corresponds with that of Class 2 game. The KPS of the 120 grain load corresponds closely with that of .25-06 Remington 115-120 grain bullet loads.
The 120 grain load would be a good choice for pronghorn antelope, whitetail deer, or any similar sized game animals, especially in open country. The recoil of this load is relatively mild, about the same recoil as the aforementioned .25-06 loads.
Hornady American Whitetail 139 gr. InterLock SP: MV 2800 fps, SD .246, Zero at 230 yards, MPBR 270 yards, 100 yard HITS = 878, KPS = 31.8, Recoil = 14.4 ft. lbs.
139-140 grain bullets are, by far, the most popular choice for the 7mm-08, with good reason. The 139 grain load above has a HITS score near the high end of the medium game range. The KPS score of the 139 grain load is quite close to 140 grain loads in the .260 Remington or 6.5x55 SE cartridges. This is the general purpose Class 2 game load for the 7mm-08, effective on any Class 2 species to beyond the MPBR of the cartridge.
The .246 sectional density of the 139 grain bullet only reinforces these conclusions. For comparison, this is well above the .226 SD of a .308/150 grain bullet and bodes well for deep penetration.
The recoil energy is well below that of a typical .308 Winchester 150 grain load in the same weight rifle. At 14.4 ft. lbs., it is below the 15 ft. lb. limit most hunters would do well to observe.
Hornady Precision Hunter 150 gr. ELD-X: MV 2730 fps, SD .266, MPBR 275 yards, Zero at 235 yards, 100 yard HITS = 1027, KPS = 37.2, Recoil = 16.2 ft. lbs.
150-160 grain bullets give the 7mm-08 Class 3 game capability, within reason. HITS scores are in the large game range, which Hornady defines as scores of 901 to 1500 for game animals weighing 300 to 2000 pounds.
(This excludes so-called dangerous game, which Hornady calls the "Big Five / Very Large Game" category, with no weight range or limitations specified. HITS scores for cartridges suitable for such animals start at 1501.)
The KPS scores for this load indicates it has power comparable to the .270 Winchester with 150 grain bullets. The sectional density of .266 indicates 7mm/150 grain bullets have deep penetration potential on large animals. However, I would not recommend the 7mm-08 for really large or potentially dangerous animals. Leave such use to the 7mm Magnums.
Heavier bullets equals more recoil, but these loads are still not unduly punishing. Their recoil levels are much like that of a .308 Winchester firing a 150 grain bullet at 2800 fps MV; this is a caliber and load I have shot a lot, without undue abuse to my shoulder.
Nosler 175 gr. Partition (hand load): MV 2515 fps, SD .310, MPBR 250 yards, Zero at 215 yards, 100 yard HITS = 1275, KPS = 42.2, Recoil = 17.8 ft. lbs.
This load, from the Hodgdon Reloading Data Center, uses 46.0 grains of IMR 4350 powder. I include it to illustrate what the 7mm-08 can do with maximum bullet weights. The velocity, energy and high SD of this load makes it capable on heavy animals (e.g. elk and moose) at reasonable ranges. KPS is like that of a 165 grain .308 Winchester load at 2700 fps MV, but the 7mm bullet has a much higher SD (.310 vs. .248 for a 165 grain .308 bullet) and consequently deeper potential penetration. Recoil is comparable with a 180 grain .308 Win. load (SD .271) at 2600 fps MV.
Reduced recoil loads
There are two reduced recoil factory loads available for the 7mm-08. The Remington Managed Recoil load uses a 140 grain Core-Lokt PSP bullet at a MV of 2360 fps. The MPBR (+/- 3") of this load is 230 yards.
The Hornady Custom Lite load uses a 120 grain SST bullet at a MV of 2675 fps. It has a MPBR (+/- 3") of 260 yards.
Both of these reduced recoil loads generate 9.6 ft. lbs. of recoil in an eight pound rifle. They have enough power to cleanly take Class 2 game out to their MPBRs.
Jack O'Connor's lessons from the field
Calculated performance numbers for cartridges and loads are useful, but the ultimate proof of a hunting cartridge is actual results in the field. JOC reports these extensively for the 7x57 in his various articles and I believe his observations apply equally to the 7mm-08, since it is so similar in ballistic performance.
I infer from the article that O'Connor owned 7x57mm rifles more or less continuously after acquiring his first one in 1934 and he used them quite a bit. (Yes, he did hunt with many calibers in addition to the .270 Winchester.) His personal experience with the caliber is summarized by this paragraph from his Gun Digest article:
"I shot my first desert ram with that (first 7x57) rifle, one of the best Rocky Mountain mule deer I have ever knocked off, and various other game \'97 all with the Western factory 139 gr. open point bullet load. With one exception, everything I shot at with a 7x57 was a one-shot kill. That was a desert mule deer which I shot in one ham as he ran directly away and on which I used two cartridges. Then about 1952, I caught up. Hunting on Idaho's Snake River with another 7x57, I picked out a nice fat doe and took a crack at her. Down the hill she rolled \'97 and also a fork horn buck that had been standing behind her."
However, Eleanor O'Connor was the leading field tester of the 7x57. Jack wrote that in 1948 he had a 7x57 with a 22 inch barrel built and stocked on a Czech VZ33 action. His wife fell in love with the rifle, so he had the stock shortened to fit her. Here is how he describes what followed.
Eleanor's 7x57mm rifle. Image from the Gun Digest article.
"This 7x57 has been her favorite rifle ever since. I have no idea how many North American animals she has collected with it, but I believe I can name the species: mule deer, Rocky Mountain goat, black bear, caribou, elk, Stone sheep, Dall sheep, Corsican mouflon in Texas and pronghorn antelope. She has also used it on the mountain sheep called urial in Iran and has collected most of the African antelope, including such large ones as eland, greater kudu, roan and sable with it on safaris in Tanzania, Mozambique, Angola, Botswana, South West Africa and Rhodesia."
"In Mozambique, our professional hunter was the famous Harry Manners. He looked askance at her little rifle, told her she was under gunned. Before the trip was over, he was calling her One-Shot Eleanor, because with the exception of a greater kudu, a handsome antelope about the size of a spike bull elk, everything she shot at was taken with one bullet. This kudu jumped into the air as she fired and I called it a heart shot. My wife hit it again as it ran and yet again when it stopped. It fell at the third shot, but it had one bullet through the heart. From its actions, I am convinced it was the first one."
How does the 7x57 (and by extension the 7mm-08) stack up against ballistically more powerful cartridges in the field? Here are Jack's observations, based on nearly forty years of personal experience.
I have heard many a fanciful tale about the incredible toughness of African antelope. After much prayer, meditation and ten African safaris I cannot for the life of me see that African game is any tougher than North American game. I have used as 'light' rifles on safari the following calibers: .300 Weatherby, .30-06, .270 Win., 7mm Remington Magnum, .338 Winchester Magnum and the 7x57. I have also used on heavier animals a .416 Rigby, 450/400 Jeffery double rifle, .450 Watts (the predecessor of the .458 Lott) and various .375 Magnums."
"As far as I can tell the little 7x57 kills African antelope, from the largest to the smallest, just as well as any of the cartridges I have used. I have, for instance, shot greater kudu with a .300 Weatherby, a .30-06, a .375, a 7mm Remington Magnum, a .270 and a 7x57. All kill well if the bullet is well placed, but the hunter who paunches his animal or breaks a leg is generally in trouble with any of them."
"Just before writing this I read a piece by a writer who dotes on the magnums more than I do. He uses the 7x57 as a dreadful example of the non-magnum. He says that, '200 yards is close to the practical killing limit of the 7x57.' He adds that this is because the energy has then fallen off to about 1,400 ft. pounds."
"Well, I've got news for the lad. Two hundred yards is not only the practical killing range of the 7x57, but also the practical killing range of the .30-06, the 7mm Magnum, .300 Weatherby Magnum and what have you. The reason for this is that very few hunters can lay the bullets into the vital area of a game animal at any greater distance, even under the most favorable conditions. In fact, I'd bet a sugar cookie that most hunters could kill stuff farther away with the 7x57 than they could with the 7mm Magnum. It would not kick them so hard. They wouldn't be afraid of it and they would shoot it better. I have some more news: game is not killed by foot pounds of energy. In fact, the energy has little to do with killing power. Animals are killed by putting in the right place a bullet that penetrates deep enough and opens up adequately."
O'Connor's Pet loads
Jack O'Connor indicated that he mostly used 139 and 140 grain factory ammo in his early years with the 7x57. He specifically mentions Dominion, Federal and Western loads. Later on, reloads with 140 grain Nosler Partition bullets became his favorite. Meanwhile, Eleanor pretty much used hand loads with various 160 grain bullets for everything.
There is something interesting about those hand loads. Jack wrote that his pet load was 45 grains of 4320 powder under 140 grain bullets, which got a MV of 2825 fps from his Winchester Model 70 with a 22 inch barrel. Eleanor favored a load with 52 grains of 4831 with 160 grain bullets, getting 2660 fps MV, also from a 22 inch barrel. (Jack just called the powders 4320 and 4831. The first was surely IMR, but the second could have been either Hodgdon or IMR. I am assuming that both were IMR powders, to make things simpler.)
The interesting thing is, according to current load tables, these were hot loads. The Nosler Load Data website lists a maximum charge of 43.0 grains of IMR 4320 with a 140 grain bullet for the 7x57, for a MV of 2768 fps. For 160 grain bullets, the maximum charge of IMR 4831 is 49.0 grains, yielding a 2648 fps MV. (These data are for 22 inch barrels, so we have apples to apples comparisons.)
Jack was willing to push the envelope a bit when reloading, as he was loading for rifles much stronger than the 1893 Mauser for which the low SAAMI pressure limit for the 7x57 was based. The 7x57 is inherently just as strong as the .270, 7mm-08 or .30-06, cartridges for which O'Connor's Winchester Model 70 and CZ rifles were designed. (There is no reason why anyone with a Winchester Model 70, CZ 550, or equivalent modern rifle cannot load the 7x57 to a MAP of 52,000 CUP / 61,000 psi. O'Connor's 7x57 loads were virtually identical to modern 7mm-08 loads. -Editor)
Summary and conclusion
The 7mm-08 did not exist, except as a wildcat, in the time of Jack and Eleanor O'Connor. Had it been introduced as a commercial cartridge when they were still active hunters, Jack might have been skeptical about the need for the new cartridge, although he would have applauded its performance. I can imagine him grousing that the 7mm-08 was not needed as long as the 7x57mm Mauser was around. Eleanor likely would have shrugged at his antics and then gone out and shot something with a 7mm-08.
Since the popularity of the 7x57 has faded, though, it is good that modern hunters have the equally effective and sensible 7mm-08 Remington to stand in for it.
I cannot close this article without a word about the writings of Jack O'Connor. I would "bet a sugar cookie" that many of those reading this article have never had the pleasure of reading anything that Jack wrote. This is a shame. "Forty Years with the Little 7mm" is an excellent example of his writing, so I urge anyone who has never read him, or who wants to get reacquainted, to read the article in its entirety. Here is the link to it: https://gundigest.com/more/classic-guns/forty-years-little-7mm
JOC wrote over 1200 articles for various outlets, but as best I can determine "Forty Years with the Little 7mm" and "Tips On Big Game Shooting" are the only ones currently available on the Internet. Both are on the Gun Digest website.
If reading these articles creates an appetite for more, there are several books still available that were either written by JOC, or are collections of some of his articles. For instance, "The Lost Classics of Jack O'Connor" (edited by Jim Casada) is a collection of forty articles that JOC wrote for Outdoor Life magazine and which have not been reprinted in any other collection. This title, available directly from Safari Press or through Amazon books, would be a good choice for anyone wishing to become more familiar with the work of the late Dean of American Gun Writers.
Note: Gary Zinn and Chuck Hawks, their agents and assigns hereby disclaim all liability for damages, including, actual, incidental and consequential, resulting from use of the reloading data, information, opinions and advice contained in this article. Use at your own risk and with all due caution.
Copyright 2017 by Gary Zinn and/or chuckhawks.com. All rights reserved.