Breech Plug for Original Encore and OmegaStainless Steel Replacement Breech Plug for Thompson Center Encore and Omega Muzzle Loaders. This breech plug fits Thompson Center Arms 209x50 Encore muzzle loader barrels and also TC Omega muzzle loader rifles. Breech plugs can get crudded up and near impossible to clean after awhile... It's easier to just get a new one! Or, order a spare in case you lose your original breech plug. See accessories at our TC Muzzle Loader Accessories page.