Harris Bipods are a battle proven item found on many military rifles in the Afghanistan and Iraq theaters. Harris Engineering produces a number of great bipods, but this is the one that Charlie's recommends.
The Harris 1A2-BR is a lightweight, ultralight bipod that extends from 6 to 9 inches and weighs 11 ounces. It's made from heat-treated steel and hard alloys, has a solid base, and smooth legs. The bipod attaches to the sling swivel stud and clamps to the stud of most bolt action rifles with a conventional stock design.
Mounts to QD swivel studs on bolt action and single-shot rifles for ultimate field accuracy. Won't change zero; added weight steadies gun. Spring-loaded, telescoping legs adjust quickly, fold parallel to barrel for carrying.
Add a Picatinny mount, like the ARMS #32 throw-lever mount used by US Special Forces.