Anyone hear of Grendel II using a 6.5x47 Laupa throat?

[woohoo]

#FTW

Question for you. The shape you show above looks like what a button would look like used to rifle a BHW barrel. I looked at one with a borescope. The lands look like they are very very thin like the points of the white part of the shape above.
Is the black part of the shape above the shape of the buttons used to rifle a BHW barrel?