CLEANING THE BREECH PLUG AND VENT LINER:
1. Using a 1/8” Allen wrench, remove the vent liner from the breech plug.
2. From the vent liner side, look through the breech plug to assure that the flash hole has not become restricted with carbon build-up.
3. Starting from the primer pocket, use a #21 bit (0.159 to 0.160 inches) to open the flash hole (see Figure 8). An electric (or battery powered) drill may be necessary depending upon the amount of residue.
CAUTION – DO NOT HIT THE VENT LINER THREADS WITH THE DRILL BIT.
4. Thoroughly clean the breech plug and removable vent liner with the same solvent used to clean the bore.
5. Inspect the vent liner by looking through it and replace if necessary.