A bore guide comprised of a rear housing, an adjustable shaft having a proximal and a distal end, a tip on the distal end of the adjustable shaft, a spring housing connected to the proximal end of the adjustable shaft, a spring located inside the spring housing, and a lock insertable into a portion of a firearm to lock the spring in a compressed state. The rear housing may have a rear opening on a proximal end of the rear housing and a solvent port on a circumferential portion of the rear housing. Transition of the adjustable shaft toward the rear opening can cause compression of the spring. The lock can secure the bore guide in place and create a seal within the bore of the firearm.