Run a patch down the bore and see if it's smooth, rough, dirty, rusty.
A buddy would get a lighted arrow knock, turn it on and drop it down the bore for a better view. (I need a few too)
Can you remove the nipple or is it dirty and rusted in place.

Which TC?

"Camping places fix themselves in your mind as if you had spent long periods of your life in them.
You will remember a curve of your wagon track in the grass of the plain like the features of a friend."
Isak Dinesen