Updated: May 1, 2020
Not identical in body, but certainly in character
There exists no valid argument either way about the “7mm-08 versus the 7x57” despite being a popular topic in USA gun forums. Once the bullet is beyond the chamber maximum pressure curve (about one inch outside the case mouth) it has no memory of, or interaction with the geometric shape of the case it had just come from.
Certainly its performance on the animal you hunt will not in the farthest fiction of the mind be related to the dimensions of either rifle’s chamber from whence it came.
Background on the 7x57
While American forces with their 30-40 Krag-Jørgensen rifles in Cuba were on the receiving end of the 7x57 used by the Spanish sharpshooters, here in South Africa my forebears used the Ludwig Löwe and DWM classic against the Brits and their Lee Metford .303s - a similar cartridge to the 30-40 Krag. In both these conflicts the 7x57 was in retrospect viewed to have been the better cartridge and that this had won the fire fights. The Mauser 1893-95 rifles also were considered to be the better assault weapon by design over the Lee Metford .303, and the Krag 30-40, and that situation had won the battles.
The British blamed their battlefield losses against the South African farmers (the most head shots in any war anywhere in the world to date) on the Mauser rifle and the 7x57 cartridge, and historians of the Spanish War to this day still spin the same yarn about the converted Spanish Mauser. It is not the object of this article to test that theory because my own research into the US Army battlefield tactics in Cuba is limited.
In South Africa, however, the facts of the Second War of Independence as it is called here indeed indicate that the Mauser rifle and the 7x57 cartridge had very little to do with the outcomes of those battles. In many cases Boer Commandos were armed with Lee Metford .303s taken from captured British soldiers, and initially there were times that scores of Boers were still using their .577-450 Martini Henry black powder rifles - the ballistic twin of the .45-70, and shot those with the same exactness of aim than with the 7x57s.
Mausers used by Afrikaner farmers against the British during the 2nd War of Independence
What won the battles were the tactics used by the Afrikaner farmers (the English word for “boer”) and their sons as young a 12 years - and their marksmanship to a man. They simply shot their captured Lee Metfords and of course their Mausers a great deal better than the Brits shot their Lee Metfords. Even though as farmers, not having been military trained, their battlefield tactics were distinctly superior to that of the British war machine - and that combination won the battles. Certainly not the 7x57 rifle.
After the war (it is often said that the Boers had won the war but lost the peace) the British press in London fueled a narrative that did not blame their brave soldiers for poor battlefield tactics and poor command and control by their leaders - they blamed the Mauser rifle and the 7x57 cartridge - as if the tool in itself does the job and not the artisan applying the tool. That emotional spin was so strong that after the peace treaty every South African farmer had to hand in his Mauser 7x57 hunting rifle and these were destroyed. Thousands and thousands of them, even their 1898 8x57 sporting rifles. The Mauser was hated with a passion as if by itself it had decimated the Brits - and not the men behind the rifles employing superior tactics and distinctly superior marksmanship.
Ironically, soon after the peace treaty was signed these same farmers were given the 1903 Lee Enfield No. 1 (including 200 rounds of ammunition for free every year) because for various reasons the British High Commissioner had accepted Boer insistence that England's newest colony needed a boots on the ground, good shooting militia around the country. The Afrikaner farmers were not only allowed, but encouraged to rejoin their previous “shooting commandos” to return to the single national sport of maintaining marksmanship by means of district, regional, provincial, and finally, national competitions. In fact, up to 1994 marksmanship was an extra curriculum activity for 14 years and older boys at high school, using .22 short ammunition from a mini Martini action.
1903 Short Magazine Lee Enfield
So, the 7x57 has an emotional-historic relevance in South Africa. Before it was used in the war it was the standard hunting rifle of many farmers. The cartridge and the Mauser rifle of course to this day stand out as impeccable performers on Africa big game. Due to its low maximum chamber pressure of only 55,000 psi the rifle’s bore life is exceptional and cases can be reloaded many times more than most other big game cartridges.
Penetration of a 170+ grain bullet of good construction from the 7x57 is impressive through the heavy shoulders of big animals like kudu or eland, and as a medium (deer size) cartridge it is a pleasing performer and a pleasure to shoot.
At 13 years age my elder son carried my brother’s lightweight Musgrave 7x57 and hunted impala with me and not once did he make a mistake - possibly because recoil is virtually non-existent in the 7x57.
The 7mm-08 is an equally pleasing performer - but let me get this off my chest first: What a silly designation for a modern cartridge: ”7mm? Oh? Eight? Oh! The POINT THREE oh eight!”. If it said 7x51 mm it would be instantly recognised as a leaner brother to the 7.62x51 mm. Or if it was called the 7mm-308 like the 6.5mm-284 everybody would immediately know its ancestry. A 6.5mm-06 at least refers to 1906 when the new .30 cartridge was adopted. The mother case of the 7mm-08 does not hail from 1908. Has there ever been any other cartridge that had the last two digits of the three-decimal figure of the same .308” bore diameter as the 30-40 Krag, the 30-06, the .300 Win Mag, the .300 RUM and the .300 Short Magnums as its case designation?
Back to the relevancy and ability of the 7mm-08. In the USA the 7mm Remington Magnum was a good seller despite the fact that it simply duplicated the ballistics of the old 30-06 with similar weight bullets but with a more expensive and impressive looking case, and needing considerably more propellant. Then the .280 Remington which is a .284” was a financial failure because it was not originally called a 7mm-06 and it was downloaded by Remington to some silly level for no logical reason. Then the .284 Winchester appeared but did not do much either because it was not called a 7mm Winchester.
Then Remington produced the 6.5mm based on the .308 case, but fatally called it the .260 Remington and not the .264 Remington (or what would have now sold like hot cakes: called it the 6.5mm-08).
Logically, then the 7 millimetre based on the .308 Winchester case appeared on the benchrest scene and it sort of caught on with hunters too despite the illogical case designation by Remington. It virtually duplicates the performance of the 7x57 with the lighter (140 gr) bullets, and for many that is good enough. In the hunting field, duplicating what the 7x57 does most certainly is good enough if good quality bullets are used.
So at last a non magnum 7 mm in a short action had arrived because short actions were the new rage. The cartridge made (and still makes) a lot of sense for hunting in the USA.
Brass is everywhere, it is all-American, and the aerodynamic properties of a 7mm bullet weighing 140-160 grains was better for the bench rest shooters than a .308” calibre bullet of the same weight, and that was where it started its acceptance.
In South Africa the 7mm-08 is not often seen but indeed they are around - sufficiently so that imported factory ammunition is available in all the big centres but not necessarily out in the hunting areas. If it has one theoretical shortcoming it is the short neck that by design was necessary to allow a case capacity to duplicate the thermo dynamics of the 7x57.
This means that the heavier (longer) bullets preferred by local hunters significantly protrude into the case, stealing potential volume from the propellant. This is particularly so with the monolithic solids like the Peregrine, GS Custom, Rhino and some 5 other local brands of monolithic bullets.
That issue is neither here nor there in practice because with the impressive penetration impulse of the monolithics a 160 gr bullet at the same velocity as the locally popular cup&core 170 gr will have the same penetration if not better. Even the 170 gr monolithic at lower velocity will still have better on-animal performance as a C’nC design of similar weight.
In the USA which one to buy? Do what we do here. Ask for the rifle in the shelves that speaks to you from there. Close your eyes and shoulder it. If it feels good, open your eyes - and if the sights are naturally aligned only then look on the barrel to see which cartridge it shoots. No matter which of these two under discussion it is, take it. You will never be disappointed with either.
Here in SA? Without a doubt the 7x57.