STOCKING UP

Whether you’re thinking of upgrading your favorite bolt gun or building one from components, a chassis system offers a compelling combination of performance and versatility that’s difficult, if not impossible, to get from a traditional stock. The basic characteristics that differentiate a chassis from a stock are a monolithic bedding area and an integral magwell.

CHASSIS VS. STOCK

For those wondering how a chassis and a stock differ, basically, it’s in two ways. First, in a traditional stock, the trigger guard and magwell (or internal magazine) are a single, separate component called bottom metal that’s bolted to the action with the stock sandwiched between them. A chassis is an all-in-one assembly that combines a stock, magazine well, and trigger guard into a single component.

Second, chassis and stocks differ in their method of bedding the action. Bedding the action means making sure it doesn’t move in the stock or chassis between shots. Compressible organic or hand laid stocks generally benefit greatly from the use of bedding compound, while uncompressible aluminum chassis are machined with a bedding area that provides the surface area contact to hold an action in place without adding bedding material.

BEDDING BASICS

The interface between the action and a chassis is an integral bedding surface. The aluminum bedding area is machined into a shallow V or a gentle radius that cradles the steel action in two long lines along its length. As the action screws are tightened, the action is pulled down into the V and held fast. The big benefit of installing a barreled action in a chassis is that it’s that simple. Screw two bolts down, torque to spec, and head to the range. Changing actions? Same procedure. The drawback of a universal fit using a V-block appears when torquing an action into the chassis. V-blocks can create a fulcrum point where the action body radius tapers at the tang, as evidenced by the tang diving, tip-down, when the rear action screw is tightened. The hotspot can deform some actions enough to cause bolt bind or other issues.

Another method is radius bedding. Instead of the action riding on two rails, radius bedding means the bedding block is cut to match