Join Date: Sep 2008
Location: Bavaria, Germany - the center of 15th and 16th century gunmaking
Sixl's measurements of the barrel lengths do include the tubular sockets. What you call a chamber, i.e. the breech originally receiving the powder and ball, is covered in any case.
My scanner is out of order at the moment but as soon as it is back at work I will publish a scan of all those data.
Dont' expect too much of them though, they are extremely bewildering, even to an expert, and I am afraid I might be of very little help to you ...