The contour I set up with Lilja tapers from .665" at the end of the forearm to .610" at 22". IIRC, the factory taper goes from .665" to .565" at 22".
I don't have any barrels at the house for measurement....but I think the taper stops at .610" too. You could go longer than 22" if you wanted, but 22" is plenty for me on a Montana (84M).
