I have to disagree with Bill of the 45th, I would not inlet the barrel and breech plug separately, this can only lead to problems. I would inlet the breech end of the barrel without the plug in it. After it is fit real good along the very breech
end of the barrel, I would make a pencil line along the top flat on each side, then check the length of the stud on the plug
and draw a line across the stock...........you should then have an elongated box drawn on the top of the stock. I would
then inlet a tapered hole similar to the stud on the breech plug, but, keep it undersized, and inlet this area all the way
down to the bottom flat of the barrel. Then install the breech plug, put some inletting black on the stud and insert it into
the undersize inlet...............remove the black wood, and do it again, until the tang is flat on the stock. When you reach
this point, drawn a line around the tang and inlet that....once again, undersize, and using inletting black, keep removing
wood until it's all the way down. Should take you about an hour to an hour and a half................Don