7mm-08 Beats 308 Win!

K-7m-08-Rem.jpg
K-7m-08-Rem.jpg

K 7m-08 Rem

In a recent blog, manly man Richard Mann indulged in a weak embrace of the 308 Winchester as his choice for all-round, do-everything rifle cartridge. Like the groom at a shotgun wedding, he says “I do” more out of a sense of self preservation than conviction.

Well, I can’t blame Richard for cold feet, but I can blame him for not jilting the plane Jane 308 Win. for a more stimulating and — as it turns out — EFFECTIVE cartridge such as the 7mm-08 Remington.

Mann is right; the 308 Winchester can do it all, but it IS boring. It’s also less efficient than its .284-caliber offspring. The 7mm-08 Rem. may be just the 308 Win. necked down, but what a difference this bit of pre-nuptial necking makes. Flatter trajectory, less wind deflection and MORE ENERGY downrange where it might actually matter. The 7mm-08 Rem. is the modern version of W.M.D. Bell’s .275 Rigby, the British title for the 7x57mm Mauser. With that particular 7mm, Bell shot some 1,000 elephants and plenty of buffalo, lions and similar creatures judged too stout for anything less than a 375 H&H Mag. these days.

Not much size difference between 7mm-08 (L.) and 308 Win., but enough that the more efficient .284" bullets win the ballistic battles.

 I don’t care how expert a shot Bell was, if his 7x57 could routinely fell Cape buffalo, I’ve a strong hunch the 7mm-08 (which generally shoots 100 fps faster) can terminate an elk, moose, black bear or anything Rich plans to Mann-handle with his overrated 308 Win.

Let’s take a closer look at these two cartridges. Richard likes a Nosler 165-grain AccuBond in his 308. OK. I’ll take Nosler’s 160-grain AccuBond in my 7mm-08. We’ll zero each 3 inches high at 100 yards to maximize Point Blank Range for an 8-inch target “kill zone.” We’ll mount our scopes 1.5-inch above bores. Let’s launch both projectiles at 65-degrees F. in a 10 mph right angle breeze and see where they end up.

Ballistic Chart

As you can see, there’s not a huge difference, but the 7mm wins the race and the punch. Most significant is its reduced wind deflection at long range, one of the most difficult trajectory components to judge and correct in the field. I personally don’t think the 7mm’s 84 f-p kinetic energy advantage at 600 yards makes any difference to the game struck, but for those of you who do… well, here's evidence that the heavier bullet and larger caliber aren't always the harder hitters. And the 308 Win. isn't the best long range sniping round, either. What sniper wants 4 more inches of drop and drift at 600 yards? In exchange for what advantage, 84 foot-pounds less punch? 

What might sway some shooters to the 7mm-08 Rem. is it’s slightly reduced recoil. In 7-pound rifles the 7mm puts out 17.18 foot-pounds free recoil, the 308 kicks with 17.94 f-p. Again, not a huge difference, but for some sensitive shooters…

The 7mm-08 Rem. can handle big bull kudu better than kudu can handle the 7mm-08.

Mann does point out that the 308 Win. has the advantage in ammo availability, including reduced power loads for practice. True, but as a handloader, I don’t care much about that. As for the convenience of finding local ammo on an exotic hunt when an airline conveniently "loses" your ammo, don't forget that some countries don't allow the 308 Win. because it's considered a military round (7.62 NATO.) 

So what do you think? Has Richard fallen for the old 308 Winchester myth? It's an adequate cartridge that can do what's advertised, but there are many better. My contention is the 308 Win. is popular mostly because it is a military cartridge. Lot’s of conscripts and volunteers learned to shoot with it. Lots of 308 ammo and brass is available. Every gun maker chambers for it. But that doesn’t mean the 7mm-08 isn’t superior. Because it is.

If the slight ballistic advantages of the 7mm-08 Remington don’t inflame your passion, wait’ll you read my upcoming blog on an even better, faster, harder-hitting short-action cartridge, the 6.5-284 Norma. 

(You can read Mann's blog on the 308 Winchester here.)

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