Bedding involves
molding an
epoxy-based material onto the stock recess to fill away the gaps within its contact surface with the
receiver (known as
glass bedding), and/or inserting a metal cylinders (which act as
compression members) around the action screws to reduce compressive shifting (known as
pillar bedding). The receiver and the stock are sometimes fastened indirectly through an intermediate piece (usually made of rigid materials such as
aluminium alloy) known as a
bedding block, which multifunctionally serves as a larger pillar, a bedding surface and even recoil lugs. The contact interface on the stock may also be substituted by a metallic bedding frame known as a
chassis, which is either embedded within the stock, or even completely replacing the stock like the lower receiver on many modern modular
semi-automatic rifles. Skim bedding refers to an adjustment of a glass bedding job, usually after wear and tear from use, which consists of removing a small layer of the bedding material — usually up to around — and adding new bedding material on top of that. Several different bedding methods can be used depending on the type of stock, desired results and level of experience of the person attempting to perform the bedding. Methods include: • Full contact bedding of the action with the barrel floated. • Full contact bedding of the action and the barrel. • Full contact bedding of the action with a pressure-bearing pad for the barrel. • Pillar bedding of the action with the barrel floated. • Full length aluminum action bedding block. Full contact bedding of the action with the barrel floated is a very common method for long range rifles with a heavy barrel. A
free-floating barrel will generally produce the greatest accuracy. However, a pressure pad under the barrel just forward of the action can sometimes improve accuracy by acting on barrel harmonics and reducing stress on the action from the weight of the barrel. Pillar bedding can be used to float the action as well as the barrel, but the process is more difficult. ==Precautions==