The KRG C-4 Customizable Chassis for Precision Rifles: Review

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Chassis for precision rifles are ubiquitous, but they are not all created equal. We’re several years into the precision rifle boom, and smart chassis manufacturers are continuing to evolve as the customer’s education improves and needs increase. Cranking out a chassis with a V-block bedding system that takes AICS-pattern magazines used to be good enough. That is no longer the case. Kinetic Research Group (KRG) is an Idaho-based firearm and firearm accessory business that caters to the precision shooting community. KRG was started and is still run and owned by a few snipers from 5th Special Forces Group. Their training and background shows in the products they design and manufacture, especially the new C-4 chassis seen here. This chassis is machined from a 45-pound block of billet aluminum, which is one of the contributing factors to its expense. KRG went to this extreme because they wanted as rigid a chassis as possible. A solid piece of aluminum eliminates any flex from multiple pieces or a hinged buttstock. That flex is unwanted movement that can affect the rifle’s point of impact, especially at long range.

One thing KRG understands is that reliable bolt-action operation starts with the magazine. The C-4, like just about every other chassis out there, accepts either AICS or AW magazines. The huge differentiator between the C-4 and every other chassis is the C-4’s ability to tailor or fit the magazine well to the specific magazine in the shooter’s possession. One ugly truth about magazines is that even though they all claim “AICS” footprint, the size variation from one magazine to the next can vary considerably. This problem gets worse when comparing magazines from different manufacturers or magazines made from different materials. Since just about every chassis is machined from aluminum, resizing the magazine well requires developing an innovative solution.

No solution to this issue is more comprehensive or effective than the one found in KRG’s C-4. The magazine well in the C-4 has a two-screw adjustable catch that allows for varying magazine height placement. Anyone desiring to shoot an AW magazine in a two-lug action should strongly consider the C-4 just because of the precise fitment possible with this chassis. An AW magazine teamed with a two-lug action requires the magazine to seat as close to the bolt body as possible. No chassis offers better height control than the C-4. The magazine catch has a .11-inch adjustment range, so getting any AICS or AW magazine to fit won’t be a problem. The two screws that straddle the catch are also under spring tension, so there’s no chance the catch will come out of adjustment on its own.

The front of the magazine well also allows for sizing adjustment. Loosen the two screws holding the front of the magazine well in place, and the front of the magazine well can move either close to or further from the magazine catch. Being able to make this adjustment allows the shooter to both accommodate the variations found in AICS and AW magazines as well as tailor the force required to activate the magazine release. Finally, there are two leaf springs that flank the magazine when inserted into the well. Some shooters are passionate about the magazine having no rattle once inserted but still want easy removal. These two springs make that possible. The two springs also help support the sides of AW models and do a better job of accommodating the flex in the double-stack magazine when it’s loaded to capacity.

Forward of the magazine well is a thick, wide, 17-inch forend that has an integrated ARCA rail along the underside. The underside has attachment locations for M-LOK, the Really Right Stuff R-Lock system, and KRG’s own Delta Lug. The sides of the forend can accept rail attachment, M-LOK, and KRG’s future mini Delta Lug. No forend has more attachment options than the C-4. Additionally, there are three options for forend enclosures based off the optic’s sunshade use and the scope’s length. These enclosures have threaded holes on top to attach sections of rail for use with night vision and thermals. The C-4 also has a weight system that takes the 6-pound bare chassis to over 12 pounds! Two forend weights fit in the bottom of the barrel channel, two smaller weights attach to either side of the buttstock, and a single, heavy length-of-pull spacer finishes out the package. The weight system makes it easy to balance the rifle for optimal use on a barricade or just to weigh it down as much as possible.

The C-4’s buttstock offers unprecedented adjustment. The quick-adjustment features extend to the buttpad height, length of pull, comb height, and toe height. Buttpad cant is also adjustable via screw placement. Toe height is the most unique, with only the C-4 offering it. Anyone who shoots a lot in the prone position or from a bench will see immediate improvement in group sizes, because squeezing the rear bag for small elevation corrections is no longer necessary. KRG’s C-4 is the most rigid and most configurable chassis on the market. All of the adjustability in the magazine well sets it up for the most effortless and reliable feeding possible. Anyone desiring these features from a chassis needn’t look any further than KRG.

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