I respectfully wish to lodge a couple caveats to assertions made by friend Skirmisher in his thoughtful post in this thread. The statement that "all walnut used by the government for rifles an(sic) muskets came from Pennsylvania until the Civil War" appears to be contradicted by the NPS website on woodworking at Springfield Armory. Therein it is stated Springfield initially obtained its supplies of black walnut locally and then from "the mid-Atlantic states", of which, of course, Pennsylvania is one. Surely contractors who produced M.1816 muskets, such as Adam Carruth of Greenville, S.C., would have found it inexpedient to have bulk wood shipped from Pennsylvania over primitive roads in the pre-railroad days of 1819 when black walnut abounded much closer.
Friend Skirmisher also asserts "100 percent of Confederate muskets manufactured at the Richmond and Fayetteville armories were made from Pennsylvania walnut plank" captured by Virginia troops at Harpers Ferry. Initially, I note no muskets were made at Fayetteville and much of the stock material captured by Virginia at the Ferry was finished and semi-finished, not just planks. Plus the inference that all Harpers Ferry wood came from Pennsylvania is addressed in the paragraph above.
Further, in the spring of 1862, a result of a a very questionable decision, most of the gun stock machinery for producing the Richmond family of weapons and Fayetteville rifles was shipped south and eventually set up in Macon, Georgia. Pretty-much all the remaining captured wood from Harpers Ferry was sent there and finished stocks shipped to Richmond and Fayetteville. But Fayettevilles and Richmonds WERE manufactured from southern sourced walnut, too, though the obtaining of that local walnut was generally a dismal episode. Paul Davie's seminal book "C.S. Armory Richmond" contains several proofs of this, a few of which follow. Letter from Danville, Virginia to the superintendent of armories in Richmond makes note of "the stocks sawed out by contractors" in the Danville vicinity. (page 159) A letter from Richmond to southern contractor Carver & Miller accepting 2236 stocks and another from Richmond stating "we have been buying walnut lumber here & sawing out the stocks" (page 167). February, 1864 letter stating Richmond is sending ten thousand board feet of black walnut to Macon to be shaped into musket stocks. It is notable this is unseasoned wood and thus could not have been from the 1861 Harpers Ferry capture (pages 189 and 191).