yeoman
Just thinking about correcting a term you are using, and I might be wrong, the term "snail channel" was the trem that TC used to describe the flash channel under the nipple to the rear of the barrel so that you might shot pellets in a Hawken. The normal flash channel comes in at a 90 degree angle to the powder and was not reliable to set off pellets. The channel is internal in the breech plug.
Looking at the breech plug cavity, if you have a bright pen light you can shine that down the barrel and get a look at the cavity, or if you have a fiber optic light you can remove the nipple and stick it in there and shine light into the cavity. Most modern breech plugs now days have a clean-out screws that give you a better view of the plug. Another thing you might do is feed a pipe cleaner into the nipple whole and into the barrel.
Personally if the bore looks good the BP will probably be OK also. And like FG said check the nipple threads.
From your first description of the gun - I would say get it!
snail ignition chamber
