Chambered ( Patent ) breeches have a strong potential to create ignition problems.
They can be harder to clean than traditional breeching arrangements. You definitely need to get a copper bore brush that is a kind of a loose fit in the reduced inside diameter of the antechamber, attach it to your threaded rod end, and twist it around CLOCKWISE a few times in the cleaning process.
Even dry brushing the reduced chamber every few shots is beneficial. Just be sure to tip the barrel down and whack the side of the gun with the heel of your hand a few times to jar out any chunks of fouling you may have dislodged so they don’t get pushed back down the barrel when loading the next shot.
Chambered breeches can obviously be made to work, they just require more work to do so, in most cases.
I swore off of them decades ago. Give me a plain, flat-faced breech plug any time.
