I dont have a 6gt but do run a 6.5x47 with their modular dies. I've had Redding and Whidden dies and nothing compares to the SAC. I think the neck/shoulder bushing makes sure that everything is perfectly aligned and concentric and creates almost perfectly concentric cases. I also like their shim system as it makes it very easy to adjust headspace with a .001 shim. They are pricy for sure but its hard to go back to anything else after using these. They also happen to chamber my barrels, so the dies work great on my rifle but even before they did, their dies are really well headspaced and means to work with Redding competition shell holders . The whidden click dies with the SAC regular bushings are a close second - especially if you have a smaller chamber where you think you have to shave the bottom of the die down. Whidden purposefully makes the die bodies smaller but they dont work with shell holder sets due to this very reason. I use mine on an Area 419 press so not sure if it wold be any different on a progressive.
