With the buttplate off, if you cannot tell from the grain, smell it. Walnut has a distinctive, rather bitter smell.
I'm Sorry, I couldn't help myself on this one..
if you read your post..."with the buttplate off" ..that leaves you with the bare butt... you say "smell it"..."distinctive, rather bitter smell." my wife just took our baby nephew home and you are correct ,butts do have a ..."distinctive, rather bitter smell."
maybe thats why the buttplate was invented
Again I'm Sorry, all in fun..LOL---Jim--- It was a good way to identify the wood ,that i never even had given thought to b/4 ,Thanks for a good tip...and a free laugh..