New Dimension Switch-Barrel Rifle from Thompson/Center

At Media Day right before SHOT Show, Thompson/Center Arms unveiled an innovative hunting rifle that features interchangeable barrels and multiple bolts. This allows a single gun to shoot a wide range of chamberings — from .204 Ruger all the way up to the large, belted magnums. The gun employs some unusual engineering, with an AR-type barrel nut on a barrel extension which contains the bolt-lug recesses. There is no conventional recoil lug. Instead a slot on the underside of the barrel extension mates to a metal bar molded into the stock. With the supplied tools, the entire gun can be assembled or disassembled in under one minute (in the Video, a T/C rep assembles the gun in 55 seconds.)

T/C’s Dimension rifle is definitely innovative; there is nothing like it on the market anywhere near its price range (MSRP is $648.00 with tools). For a walking-around deer hunter who is satisfied with factory barrels, and who doesn’t shoot with a rear bag, the gun will probably have appeal. On the other hand, varminters won’t be impressed — the stock won’t work well with a bipod or rear bag, and T/C will be the only source for barrels. The nature of the design, for practical purposes, precludes the use of affordable 3rd-party barrels. You won’t be able to buy a Shilen or PacNor prefit barrel, as you can for a Savage.

Factory Promo Video (Loud Soundtrack — turn down speakers before playback!)

Action Features
Pro: One size fits all — single hard-anodized aluminum action can be used to shoot multiple chamberings from .204 Ruger to .300 Win Mag with bolt, barrel, and magazine swap. For all chamberings, T/C guarantees 3-shot accuracy of one MOA with premium ammo.
Con: You have to replace complete bolt assembly to go from one family of cartridges to another (e.g. from .308 Win to Magnum). This is much more expensive than swapping a bolt head on a Savage.

Barrel Fitting
Pro: Barrels can be quickly exchanged using provided tools.
Con: Bolt recesses are machined into barrel extension section, so barrels must be supplied by T/C. We were told that both bolts and barrels “absolutely have to come from Thompson/Center”.

Stock Features
Pro: Stock is lightweight with rubberized surface texture — good for wet climates.
Con: Stock is ugly. Forearm too flexy to use with bipod. Concave arc on underside of buttstock is terrible for use with rear bag. Stock finish tends to retain dust and grit.

Scope Mounting
Pro: T/C offers a bridge scope base that mounts to the barrel (like on Blasers). This allows an optic to stay with a barrel — so you could have a low-power close-range scope mounted and zeroed on one barrel, with a higher-power variable scope on another barrel.
Con: If you keep optics on the barrels, you need to buy a separate bridge for each barrel. That’s an added expense, plus many hunters can’t afford multiple scopes anyway. Thankfully, conventional Weaver bases can be fitted on top of the action.

Commentary: On viewing and handling the rifle, and watching the assembly process, it was obvious that some intelligent, clever engineering went into the gun. The AR-style barrel engagement system functions very well — the whole gun can be disassembled in under one minute. T/C provides some fairly sophisticated assembly tools with the gun, including wrenches that automatically set correct torque values. That’s cool. The gun is relatively light and balances well. On the other hand, the stock design fails in many ways. The fore-arm is short and too flexy for serious use with bipod. The curving underside of the buttstock is a odd-looking, but what is worse, the curve is just about the worst possible profile for use with a rear sandbag. Most observers thought the gun was ugly.

T/C Dimension Caliber Groups
The T/C Dimension LOC™ System has 7 parts — a universal stock and receiver that accept multiple barrels, magazine groups (magazine and housing), bolts and bridge scope mounts. Dimension hand tools work with all Dimension rifles. Interchangeable parts are stamped with letters: A, B, C or D. Match the letter on the barrel with the one on the bolt and magazine group.

A Family: .204 Ruger, .223 Rem
B Family: 22-250 Rem, .243 Win, 7mm-08 Rem, .308 Win
C Family: .270 Win, .30-06 Sprg
D Family: 7mm Rem Mag, .300 Win Mag