IMO you guys are about 10 years or so late to the show.
My 18" 6x6.8 runs 3373 with 58vmax and 3070 with 70NBTs. That's with virgin Starline brass and 8208 powder. Its definitely not a hot load and 8208 is slower than 335 that you all used for your data.
Bottom line, ballistic performance is almost identical with zero downrange difference between the two, everything proprietary to you guys. 6x6.8 is much less trouble, more available components and more barrel makers and smiths with reamers so I'm staying in the 6x6.8 camp but good luck guys with your endeavors.
