After the recent thread and my experiance with a TC Black Diamond breech plug, I thought I would would post a picture of these breech plugs.

These are the plugs that I use and all of them have the sealing surface both on the BP and in the barrel. As I indicated in the other thread when I handled that Black Diamond plug I was taken back a bit - because I really questioned if the tape system would work on it.

For me there are 3 keys to this system working:
1. And the most important are the two faces matching up...
2. Turning the plug in slowly and smoothly - if it catches or snags - it will be compromised.
3. Verify that tape is all the way around the bottom of the barrel trapped between the two sufaces. Use a pen light or bore light to make this verification. The tape must be compressed between the two faces but not so tight that the tape is cut.