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The Sixes: Too Small?

Accuracy always trumps energy. But with 6mms you needn’t give up hard hits. Just stiff recoil!

Excerpt from Fair Chase Magazine
By Wayne Van Zwoll, regular contributor, photos courtesy of author
From left: 6mm BR, .243 WSSM, 6mm Creedmoor, .243 Win., 6mm Rem., .240 Weatherby.

The bullet didn’t drop as steeply as the kid expected. Stung on the withers, the buck jetted off. Cycling the bolt, the kid squirmed sideways prone for another shot. The pronghorn paused so far away the mirage floated its spindly legs. Fearful he’d again over-correct, the kid forced the Lyman’s wire onto hair. At the Remington’s crack, the buck melted into the sage.

Poking through Midwest woodlots hadn’t taught me much about distance. A move to pronghorn country begged a scoped rifle. The Model 722 in .244 seemed ideal. I counted just over 400 paces to the heart-shot buck and marveled at the effect of my Lilliputian 90-grain Core-Lokt.

First buck! Gentle recoil in lightweight rifles makes the sixes a smart choice for beginning hunters.

We think of hot 6mms as modern, but the first this side of the Atlantic appeared in the 1895 Lee straight-pull bolt rifle. About 15,000 were produced. The .236 Navy, or 6mm Lee Navy, had a 112-grain bullet that required a sharp 1-in-7½ rifling twist and loafed downrange at 2,560 fps. In 1935, the Lee Navy was dropped, and the .220 Swift appeared on its semi-rimmed hull.

By the early 1920s the British house of Holland and Holland had the .240 Flanged Nitro Express and the .240 Belted Nitro Express, or .240 Apex. Both fired 100-grain .245-diameter bullets, the belted version at 3,000 fps, the flanged (for double guns) at 2,900. The Purdey shop introduced its .246 Flanged, with 100-grain .253 bullets at 2,950 fps, two years before the 1923 debut of the .242 Vickers Rimless Nitro Express with .249 bullets at 2,800. About then in Germany, Halbe and Gerlich made rimmed and rimless versions of the .244 Halger, a necked-down 6.5x57 that allegedly drove 87-grain .243 bullets at a scorching 3,700 fps.

Whimsical pre-war shifts in bullet diameter limited the use of 6mms. In 1955, American engineers settled on .243. At the same time Holland and Holland necked its .300 to fashion the .244 Belted Rimless Magnum. It hurled 100-grain .244 bullets at speeds approaching 3,500 fps. 

U.S. wildcatters gave us the 6mms that now define that clan. Fred Huntington, Jr. was one. Born in 1912 in Oroville, California, he was offered his father’s laundry business after graduating high school.  He chose instead to swage .22 bullets with a set of Vickery dies and jacket them with spent rimfire cases. Then he got the idea of manufacturing dies. Captain Grosvenor Wotkyns, a wildcatter with the .22 Hornet to his credit, snapped up a set of Fred’s first dies, as yet nameless.

“Why not call them Rock Chuck Bullet Swages?” suggested the Captain. Surely, many bullets from those dies would harass the yellow-bellied marmots westerners called rock chucks. For brevity’s sake, Fred trimmed Wotkyns’ label to RCBS.

In 1943, Fred Huntington, Jr., founded RCBS to make handloading dies and tools in Oroville. He designed what he called the .243 Rock Chucker round on the .257 Roberts hull, with a 32-degree shoulder replacing the 21-degree original. Field & Stream shooting editor Warren Page had keen interest in the sixes. In 1953 he wrote to R.T. Davis at MGS Bullets: “Right now I am messing around with the 6mms [specifically] a .243 Rock Chucker [and] wouldn’t fall over dead if sometime there were a commercial cartridge using that bullet diameter….” Remington’s .244 would come two years later, essentially Fred’s Rock Chucker with a gentler 26-degree shoulder.  

Concurrently, Page and Mike Walker developed the Page Pooper on the .308 hull, a blueprint for the .243 Winchester, also introduced in 1955. 

Early factory loads for the .243 featured 80- and 100-grain bullets, rifle barrels 1-in-10 twist. The .244 came out with 75- and 90-grain bullets, in barrels rifled 1-in-12. Rumors soon had it that .244 rifles failed to stabilize bullets deer hunters favored. As my first Remington shot well with hunting-weight missiles, I dismissed both the slight weight differences and that indictment—until decades later I picked up another 722 that didn’t like anything heavier than 85 grains. Remington pirouetted in 1963, fielding a new 6mm, factory-loaded with 100-grain bullets. This round is identical to the .244, but Remington barrels marked 6mm are rifled 1-in-9. Ballistically the 6mm and .243 are peas in a pod, albeit the .243 has always outsold its rival. Short actions require deep seating of heavy bullets in the larger 6mm hull; but I’m still sweet on Remington’s cartridge. It was a 6mm rifle from Arizona gunmaker Patrick Holehan that downed my best Sonoran buck.

Flat flight and gentle recoil in lightweight rifles make the sixes a natural choice for big, 
open places.

Hits to the forward ribs from both these sixes handily pull the rug from under deer-size game. For quartering shots and bigger animals, bullet type and weight matter more. The violent upset of many 6mm spitzers can leave them with precious little mass and diameter. Wound channels can then be too short or too slender—or random, divergent tracks of shrapnel.

Still, a small bullet lacing the vitals is preferable to a big one that misses them. Some years back, a hunting client asked if his willowy son should use a .30-06 or a 6mm on an elk hunt. He told me the lad shot best with the six. “That’s the one,” I replied. On opening morning the boy used his 6mm to kill a fat cow with a perfectly placed Nosler Partition. It seems to me any 6mm wringing 3,000 fps from 100-grain bullets is more than adequate for the likes of caribou, mountain sheep, black bears, red deer, and greater kudu.

Weatherby guarantees sub-MOA groups from its rifles in .240 Wby, with velocities to 3,500 fps!

Weatherby’s .240 Magnum is the belted equivalent of a 6mm-06 or .240 Mashburn Falcon, its 80-grain bullets clocking 3,500 fps, 100-grainers nearly 3,400. The .240’s belted 2½-inch case with radiused shoulder has a head diameter of .473, same as an ’06 (not .532, as on magnums from the .375 H&H).

Introduced in Weatherby’s Mark V rifle, the .240 has made the logical leap to the more affordable Vanguard on the slick, sturdy Howa action. My .240s in Series 2 Vanguards, Back Country and Synthetic versions, weigh 6 ¾ and 7 ¼ pounds. Hunting rifles. I scoped them as such, with a Leupold VX-2 3-9x33 and a Minox ZA-5 2-10x40.

Norma still makes Weatherby-branded ammo for the .240 (and other Weatherby magnums). A 100-grain Nosler Partition at 3,400 fps brings 1,000 ft-lbs to 500 yards, where it still clocks 2,200! At 300 yards it packs as much energy (1,550 ft-lbs.) as 165-grain spitzers from a .30-06! Two other factory loads are currently listed: an 80-grain Barnes TSX at 3,500 and a 100-grain Hornady Spire Point at 3,200. I fed earlier loads to my Vanguard 2s at the range.

 Rifle Load Group Size
 Back Country: 85 TSC .70
 Back Country: 95 Ballistic Tip .95
 Back Country: 100 Spire Point .70
 Synthetic: 85 TSX .75
 Synthetic: 95 Ballistic Tip .80
 Synthetic: 100 Spire Point 1.45

Other frisky 6mms have popped up in the .240’s wake. The wildcat .240 Hawk boasts 4 percent greater case capacity. A rifle gunsmithed by Fred Zeglin gave me an honest 4,000 fps from an 80-grain bullet! The utility of that load is arguable; not so its chalk-line arc!

Target shooters choose more modest hulls. The 6x45, introduced in 1965, is a .223 necked up, a benchrest darling that became popular with a wider range of missiles for hunters with AR-15s. The 6x47, circa 1974 on the .222 Magnum case, gained its reputation after its commercial debut as the 6x47 Swiss Match in 2001. Heavy (107-grain) bullets suited it to ranges of 300 meters and beyond. During the 1970s, benchresters Lou Palmisano and Ferris Pindell necked the 7.62x39 Soviet to produce the 6mm PPC. The squat, efficient 6mm Remington BR—essentially a shortened .308 hull with a small primer—came from Mike Walker in ‘78, nine years before the PPCs went commercial. The 6mm International, or 6mm/.250 Savage, predated the .243 and .244 by a decade. Texas marksman David Tubb later refined it to produce the 6XC, for pestering plates at distances measured in light years. 

Wayne killed this Coues’ buck with a 6mm Rem. built by ace Arizona gunmaker Patrick Holehan.

Winchester’s .243 Super Short Magnum appeared in 2005. While WSM rounds have prospered, WSSMs have floundered. They chamber just a trifle smoother than biscuit tins. Their truncated powder columns are an answer to a problem pointed out by someone now covering his tracks on Facebook. The 6mm Creedmoor has brighter prospects. Barrel-makers are wearing out reamers chambering for its 6.5mm parent. But despite its vaunted superiority at long-range plate-pocking events, the 6mm Creedmoor will hardly upend Winchester’s first .243, with its 63-year field record and throngs of enthusiastic fans. Consider the fortunes of Remington’s .280 three decades after the debut of the .270 Winchester. Ballistic twins. But the .280 never approached the .270 in sales. The great unwashed were loath to abandon their pre-’64 Model 70s, their Mannlicher-Schoenauers and Husqvarnas, Sakos and commercial Mausers in .270. 

Therein lies a cautionary tale for those who would welcome more sixes. Perhaps we have enough.

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