Sorry, but not a good idea...
Pistol/revolver grips are doable, but not particularly easily.
Wood for stocks has a very specific set of requirements and pecan covers almost all of them well... But that little thing about longitudinal shock rsistance...
Tough, hard, dense, flexible, shock resistant, and so much more just cannot overcome "Unstable in service" and that is why you will never see a pecan stock.
There are cases where it could work, like a stock for a very low-recoiling rifle. But the simple fact is the wood is so unstable the stock will be a problem at some point.
And all of the above presumes the wood will be cut and cared for as it dries and settles in over at least 10 years.
Pecan is far less stable than the rest of the hickories, too.
There are many uses for hickory every bit as difficult and technical as gun stocks, but the physical properties match up.
