The popularity of 6mm cartridges has waxed and waned over the decades, but appears to be peaking again.
What are the 6mm Cartridges:
- 6mm Lee Navy
- 6mm Creedmoor
- 6mm Remington (.244 Remington)
- 6mm Apex
- 6mm PPC
- 6mm BR
- 6mm AR
- 6mm XC
- .243 Winchester
- .243 WSSM
- .240 Weatherby Magnum
- .244 H&H Magnum
- 6mm SAW
- 6mm Dasher
In 1955, both Remington and Winchester introduced a 6mm cartridge. Remington dubbed theirs the .244 Rem., while Winchester went with .243 Win. It was a different time back then … a time when versatility in a rifle and cartridge was the mantra. The .30-06, for example, was venerated as the king of cartridges because it could take on any game anywhere in the world but for rhino, Cape buffalo and elephant. So, the prevailing sentiment of the day was that one rifle, plus a .22 caliber of some sort, was all a guy needed.
It was also the age of the vertical “gun magazine.” Now, those firearms aficionados with more than just a passing interest in guns and hunting, which included me, had access to all that was new and exciting gun-wise. It was then — the late 1950s — that I developed into a full-fledged rifle weenie. I devoured every gun magazine I could get my hands on, and it was rare that there wasn’t at least one article every month in each of those pubs talking about the “War of the 6s.” But, as it turned out, it was no contest at all: The .243 Winchester had won hands down, and for good reason.
To fully appreciate what was also happening at the time that influenced the 6mm story, it’s noteworthy that varmint/predator hunting was coming of age. Not that hunting groundhogs, prairie dogs, fox and coyotes was anything new: it was becoming much more popular than it had been in the past. As for the “big game” side of the story, if truth be told, a huge percentage of America’s hunters never hunt anything larger than deer, and that was a big factor explaining the attraction to the .24 bore. A 6mm may not be the ideal deer caliber, but it’s certainly adequate out to distances that 98 percent of all deer are harvested.
The 6mm Showdown
So, the stage was set. Winchester saw its .243 as a “dual purpose” cartridge, one that was equally suited to hunting deer and vermin. The popular perception was that, with a .243 Win., you had two rifles in one. As such, the initial factory ammunition offerings consisted of an 80-grain varmint load, and a 100-grain deer load. Remington, on the other hand, envisioned its .244 as a long-range varmint/predator cartridge, and as such it offered factory ammunition loads of 75 and 90 grains.
Three of the biggest proponents of the .243 Win. were a Texas gun writer by the name of Byron Dalrymple; famed gun writer Warren Page; and Fred Huntington, founder of RCBS. Both Page and Huntington developed wildcat .24s based on the 7.62 NATO (.308 Win.) case, which were almost identical to what would become the .243 Win. As for Dalrymple, he slew a ton of Texas whitetails and coyotes, and he wrote dozens of articles praising the .243 Win. like it was the second coming.
The .244 Rem., on the other hand, got much less press, and much of it lacked enthusiasm. Here again, Page and Huntington were in the picture because both had also developed wildcat .24s based on the .257 Roberts case, which prompted Remington to choose it for their .244. Right from the get-go the consensus among the gun writers of the day was that the .243 Winchester’s 100-grain load was an excellent deer dispatcher, but somehow a 90-grain slug out of a .244 Rem. was not. That was pretty much bullpucky, but that was the general perception — and perception is everything.
Now, if you were a handloader, the situation should have been easily remedied, but it so happened that Remington chose a 1:12 twist for its .244, while Winchester went with the faster 1:10 twist for its offspring. Again, it was the writers of the day who cautioned that a 1:12 twist might not stabilize 100-grain bullets. Personally, my experience with the .244 Rem. was that it stabilized handloaded 100-grain bullets just fine. But again, there was that cloud of doubt.
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If that weren’t enough to derail the .244 Rem., the last nail in its coffin was that the Remington Model 722 in which it was chambered was a dog. Its stock had all the appeal of a 2×4, and its ungainly 26-inch barrel did not a handy deer rifle make. The .243 Winchester’s home, on the other hand, was the svelte Model 70 Featherweight with a 22-inch barrel, and the Standard Grade which had a 24-inch spout.
Remington changed the twist rate to 1:10 around 1958, but it was too late; the damage had been done. The round languished until 1963, when along with the rolling out of the buzzard-turned-swan Model 700 rifle, the .244 Rem. was reintroduced as the 6mm Rem., and with it, two new loadings: a 100-grain slug at 3,190 fps, and an 80-grain at 3,450 fps. Back then, nominal factory ballistics were established in 26-inch test barrels, so they were optimistic to say the least. And to make sure there were no stability problems, they went with a 1:9 twist!
The Then-New 6mm
From the ballistic standpoint, the .244/6mm Rem. case, being based on the .257 Roberts hull, has slightly more powder capacity than the .243 Win., and it’s therefore capable of imparting a bit more velocity. That’s borne out by current factory ammo specs showing the 6mm Rem. 100-grain load exiting at 3,100 fps, and the .243 Win. at 2,960 fps. In handloaded form, the difference is more than that. Nevertheless, the 6mm Remington has never rivaled the .243 Winchester’s popularity.
However, being the iconoclast I am, I naturally went with the 6mm Rem. It was 1965 as I recall, and it was also one of the first centerfire rifles I built after getting out of school. I purchased a commercial Mauser action, had it barreled and set it into a stock from Herter’s. Before I went on to bigger and better things, I took a mule deer, two pronghorns, three black bears and about 300 groundhogs with that rifle. I had such success with the cartridge that I acquired two more 6mm Rem. rifles: one was a Ruger No.1B, which I restocked, and the other I built on a BSA action, a Douglas barrel and a Fajen stock. Both saw action out West and in Canada.
Thirteen years would pass after the introduction of the twin 6mm’s before any competition appeared; it was in 1968 in the form of the .240 Weatherby Magnum. Being a proprietary cartridge available only in Weatherby rifles, the .240 Wthby. Mag. didn’t actually compete with the .243 Win. or the 6mm Rem. in terms of sales, but it certainly raised the bar for .24-caliber performance.
Based on a unique case best described as a .30-06 with a belt, Weatherby data shows the .240 launching a 100-grain bullet at 3,405 fps, and an 80-grain bullet at 3,500 fps. It’s a bit puzzling that there would only be a 100 fps difference for 20 grains of bullet weight. The consensus among handloading data shows the 3,400 fps figure to be optimistic to the tune of about 100 fps in a 24-inch barrel. The 3,500 fps for the 80-grain, on the other hand, appears to be doable with handloads.
By the time Weatherby came out with his .240 Wthby. Mag. (it was the last cartridge in the Weatherby Magnum family designed by Roy himself), interest in the .24s was on the wane. I think it was because there was such a plethora of new and more capable cartridges being introduced in the ‘60s that the hunting community simply lost interest. I know I did.
Also contributing to the malaise were the gun magazines, in that they were convincing hunters that having one rifle for both varmints and deer was a compromise. You needed a varmint rifle and a deer rifle — preferably one more potent than a 6mm. Today, of course, we’re in the age of specialization. We have varmint rifles, predator rifles, mountain rifles, plains rifles, bean field rifles, hog rifles, long-range rifles … and the list goes on. It wasn’t like that back then.
One Last Hurrah
The last “nostalgic” attempt at a new 6mm hunting cartridge was the introduction of the .243 Win. Super Short Magnum in 2004. Because the Winchester folks had reasonable success with the .300 Win. Short Magnum, which they introduced in 2001 — and the .270, 7mm and 8mm versions that followed — they apparently figured, “If short is good, maybe shorter yet would be better?”
Not! The .243 WSSM, along with its sibling .224 and .257 versions, were commercial flops. Only Winchester and Browning chambered rifles for the ill-fated family, and production of those, along with ammunition, lasted but a few years.
I previously singled out the hunting community as having lost interest in the 6mm, but competitive shooters have never abandoned it. Not only do 6mm cartridges dominate 100- and 200-yard bench rest competitions, but the 1,000-yard game as well. And in the Precision Rifle Series, where once the .30-caliber was king, it has long since trended downward to smaller cartridges and smaller calibers having less recoil.
At first the trend was to 7mm, then to 6.5s — like the 6.5 Creedmoor, .260 Rem. and 6.5-284. Today, the 6mm is showing that it may be even better-suited to shooting tiny groups at 1,000 yards. It is somewhat counterintuitive that cartridges like the 6 BRA and 6mm Dasher, which have less powder capacity than the .243 Win., can launch relatively tiny 105-grain VLD (Very Low Drag) bullets more accurately at 1,000 yards than, say, a .300 Win. Magnum or .338 Lapua.
But they do, and they have a good-enough record doing it that Hornady, who gave us the insanely popular 6.5 Creedmoor, last year rolled out a 6mm Creedmoor. I’ve already reviewed two such rifles and both were impressively accurate with factory ammo.
Bottom line: The 6mm may not be as popular as it once was with America’s hunters, but it’s the darling of those shooting the smallest groups at the longest ranges.
Editor's Note: This article originally appeared in the March 2019 issue of Gun Digest the Magazine.
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