Width of butt on an 1815 Turkey/bird gun from GA/SC??

[Dr. Tim-Boone]

Recognizing that there are not a lot of examples laying around to measure.... If you were building one..sort of a smoothbore precursor to the Southern Appalachian rifle, with some English and some French background, 46" OTR 1 & 1/16" at the breech.Using modified RE Davis Late English lock........got it??.......How wide would you make the butt?? 

[sz]

In that area and era, there would still have been a lot of British influence in the fowlers so I would say to go about 2" wide.  That's how the British guns were made both before and after 1815.
The butt might have been made in a simpler form, but the overall dimensions would have likely been about the same as those of the English.