Thanks for the pictures folks.

Just guessing, but if there's a dark layer in the center of the stack, is 'K' possible. I'd also think 'J' would have at least a little tilt to the stars to at least follow the pitch of the twist. Maybe not though, interesting to reverse engineer, or try to, the great patterns that can show up.

I like to watch if a barrel maker was able to maintain their pattern through the entire barrel. The good makers must have known their stuff, not to change the pattern through uneven grinding as the barrel tapered breech to muzzle.