Thompson/Center Arms Co. sprang to life in 1967 when Warren Center’s design for a switch-barrel handgun met with the manufacturing capabilities of K.W. Thompson Tool. The merger produced a new paradigm in high-performance hunting and silhouette competition handguns, which begat other single-shot, switch-barrel firearms; for starters the Contender carbine, with a buttstock and longer barrel; then the TCR 83 single-shot rifle, released in 1983; and the Encore pistol/carbine, released in 1996. In the early 2000s, the Contender was redesigned and called the G2. Along the way T/C also made a name for itself in the muzzleloading world and even produced a unique single-shot switch-barrel in that arena, too. A couple years ago, the company branched out from its roots when it began producing bolt-action, center-fire repeaters—the Icon, Warlord and Venture.
This year the company released another bolt-action repeater—the Dimension, a nod to those very same roots. Unlike the Icon and Venture, which share design elements, the Dimension is new from the ground up. Think of it as the “Contender” of bolt-action rifles.
The Dimension is, as T/C likes to say, really more of a system than merely a rifle. Using what the company calls its Locking Optimized Components, users can switch not only barrels but just about everything else on the gun. T/C personnel envision different stocks and barrel contours for the future. For now, 10 different chamberings are available in standard configurations. Every caliber works with the same receiver and stock and, if the user desires, the same scope.
Cartridge-group parts—the steel barrels and bolts, and polymer magazine kits—are identified by a letter: “A,” .204 Ruger, .223 Rem.; “B,” .22-250 Rem., .243 Win., 7 mm-08 Rem., .308 Win.; “C,” .270 Win., .30-'06 Sprg.; and “D,” 7 mm Rem. Mag. and .300 Win. Mag. To switch from one cartridge group to another, users need the entire group of parts. But switching within letter groups requires only a barrel. So switching from .204 Ruger to .223 Rem. is pretty quick. The system is fairly foolproof, too. Components for caliber families are labeled with their appropriate letters; different letter group components will not work with one another.
Complete caliber interchanges can be made in minutes with a bit of practice. The secret lies in the use of a barrel nut, the same system used on the AR-15. The sight of a barrel nut was made famous on sporting rifles by Savage in the 1950s. It’s inexpensive, repeatable and it works fabulously. When Savage introduced the barrel nut, it smoothed its lines, essentially hiding it. Thompson/Center eschewed the practice, choosing instead to make the barrel nut large and knurled.
The barrel is screwed into an extension that slides into the receiver; it indexes when a pin in the extension engages a notch in the receiver; it’s secured by tightening the barrel nut around the receiver. Clearly, this means the barrel is free-floating, which aids accuracy. What’s more, the extension is mated to the chamber and bolt with such tight tolerances that every bolt of a given cartridge family will headspace correctly. So while 10 chamberings are presently offered (and numerous others may be offered in the future), only four different bolt sizes are needed to serve them all.
Closing the bolt engages three locking lugs against shoulders in the barrel extension. That arrangement makes for a bolt throw of about 60 degrees. A conventional recoil lug is replaced by a robust slot/lug system with a bedding block that mates the barrel to the stock; the pieces are drawn together through the receiver with a torque wrench (included with the purchase of every complete gun) that tightens the front action screw. This slot/lug system also indexes the barrel precisely every time it’s removed then replaced.
The blued, chrome-moly barrels fit right- and left-handed receivers (yes, left-handed Dimensions will be available soon). Standard-caliber barrels are 22-inches long; magnums measure 24 inches; all have 5R rifling. All are standard taper for now, but the company envisions various profiles offered as options in the future.
Bolt length and diameter is the same for all cartridges, but bolt travel is modified for short (A), medium (B), long (C) and longest (D) cartridges with a groove in the bolt body. Bolts are one-piece. Only the diameter of the bolthead varies among the four families. Each is fitted with a Sako-style extractor and plunger ejector. Each is fluted and the same diameter as the locking lugs. To remove the bolt, pull it rearward, and while depressing a release on the left rear of the receiver, rotate it clockwise, turning it upside down before removing it completely from the receiver.
The single-stage trigger, borrowed from the Icon, is user-adjustable from 3 pounds, 8 ounces to 5 pounds. The pull weight on our test unit averaged 4 pounds, 2 ounces from the factory. It uses a two-position safety; the bolt can be worked with the safety engaged.
The detachable magazine is polymer. It’s a single-column design that holds three rounds in all calibers. Magazines are adaptable to different calibers with the use of an insert (think “magazine well”). One is included with the purchase of every new barrel, though users need different ones only when switching between caliber families. I experienced no problems with feeding from the polymer unit.
Recoil is not unlike that in any other gun when shooting the “A,” “B” and even the “C” calibers. But I noted something “special” when shooting the “D” calibers. Recoil is not unbearable in the Dimension. It will only become a problem if larger calibers (perhaps the .375 H&H Mag.?) are released with the same stock design. In that case, I’d like to see the alternative on the drawing board at T/C headquarters.
The barrel channel at the fore-end is wide to accommodate all barrel contours, both present and planned, which might be offered for the rifle. That eliminates the need to design multiple stocks for various caliber groups with different barrel contours. It’s so wide it reveals the mold marks even from afar—and could collect water and snow in inclement weather. That channel reveals plainly that the barrel is free-floated, which isn’t an altogether bad selling point.