I live in the Hudson Valley, and would like to make one in a few years. They were known for their long barrels, Today, I think the longest barrel that they can drill is 50" from Ed Rayl. Some of those fowlers exceed that by quite a few inches. But if that's the longest you can get, then that's the longest you can get. Maybe other barrel makers can offer other suggestions. The Grinslade Fowler book is really your best bet as a reference. Pictures of them with some close ups with dimensions. Some selected fowlers are in color. I was impressed as to the different types of fowlers there were. The book is cheap compared to some of the books on our reference shelf at around $26. ...Geo.