I'm accustomed to terms like American black walnut, French walnut, Circassian walnut, English walnut, and all of the Latin variations of 'juglans' but more recently we hear "thin shell walnut" and wonder if this is an entirely different species or just a term describing one of the above.....
Can anyone tell us something more than the fact that this term refers to the shell of the nut itself?





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this is as good an explanation a i have seen

"English Walnut Family: The English walnut family of woods- including all the various names applied to English "thin shell" walnut such as "French Walnut", "Circassian Walnut", or "Italian Walnut". "Bastogne" walnuts (hybrid cross-pollinated walnuts) are included in this group ........"

http://www.gunstocks.com/grade.html

http://www.gunstocks.com/digst.html

But then there is the Persian "thin shell" walnut that grows from the middle-east all the way into indo-China. There are some thirty or so species of walnut right here in North and South America, some of which produce 4-chamber "thin shell" nuts....
I prefer the Latin names of genus and species just so we all know what we're talking about in terms of gunstocks, in our particular world of interest.






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since the English/French walnut has its roots (pun intended) in Asia - Persian walnut is likely the same thing (see the second link)

i think the variance you see is environmental - mineral content in the soil - growing season and such

Juglans nigra is American Black Walnut. Walnuts from this species have thick shells. Wood from this species is dark with a relatively open grain.

Juglans regia is European walnut with multiple sub species, Persian, French, Bastogne, English, etc. Walnuts from this species have thin shells. Wood from this species has a relatively tighter grain. California grows many Juglans regia varieties as nut trees, and because nut production has optimum age periods, these trees are removed and new ones planted.

Stump wood from both species can be highly figured. Generally, Juglans regia is favored over Juglans nigra for gunstocks that are to be highly checkered, or checkering is to be finely spaced. Different localities have varied soil minerals and rainfall that result in mineralization streaks in the wood.