I've got an orchard at my home with plum, cherry, pear, apple, etc. and none of my trees are anywhere near large enough to use for this purpose, nor will they be within my lifetime. There are 4 pear trees on my uncle's farm that are well over 100 years old (we have the family history and even old photos to prove that they've been there forever) and I doubt that even those trees are large enough, even if they were solid and they died or we chose to cut them down.
Curly maple is beautiful and what I build most of my guns with, but I've always wanted a pear or apple stocked flintlock rifle.