Current 6mm Grendel barrel makers: BHW, McGowen and who else?

[bj139]

1/9 or 1/10 or which other... one of my questions is what twist rate is preferred. I was -- idly -- looking at a 20" barrel but still not quite ready to pull the trigger. Or the 6mm mongoose, which I think is a 6mm Grendel wildcat.

Here is a chart from RCBS.