Big article on the 6GT in the 2020 Hodgdon Annual Reloading Manual. It sits between the Dasher and the 6x47, says the article. Max load with 110 gr. Hornady A-Tip with a 2.600'' Col is 3,075 fps.
That surely hasn’t been obtainable in the few I have been around locally. It’s already been dumped by a couple guys.
To answer Jud....
My current 6BRX (Dasher twin with 30* shoulder) is running 108s at 2990 out of a 26” Hawk Hill.
The 6x47s I ran were pre 110s and most everything that was put through them were 105 Hybrids/VLDs/AMaxes. All of those were north of 3k easily in 26” barrels too.