This precision-machined gun care accessory is designed to temporarily replace the bolt assembly inside centerfire bolt-action rifles during maintenance. Its integrated rubber O-ring creates a tight seal inside the chamber to keep aggressive bore solvents from leaking into the delicate receiver, trigger assembly, or magazine well. Built with a long-wearing aluminum body and a threaded brass adjustment pin, it offers 13 inches of length to grant ample hand clearance beneath the eyepiece of large target, varmint, or long-range hunting scopes.