End grain?
There's end grain in many places on a rifle stock...not just the forend.
Grain flows through the wrist on "proper" gunstock blank-meaning you've got end grain top as well as bottom on even a semi pistol-grip such as this:
Can't think of them in terms of dimensional lumber, they're not.
Pure aesthetics IMO. More durable, probably. But unless you're in the habit of pounding the muzzle end of your stock into the ground, I don't see that as particularly relevant.