I started shooting 7mm Dak over 10 yrs ago, orig. set up for shooting 162's and 173's through a Lilja, 9t, 27" heavy contour on a blueprinted M70 action set in a custom McMillan F class prone stock topped w/a 8x32 NF NPR-2 LR. Its odd that few are into the 7 Dakota
its a great multipurpose cartridge.
If I weren't starting a 6XC build, I'd have another barrel made in an 8 twist. Can you give more detail on the Brux you used, 5R or ? Also, have you tried anything heavier than the 180's ?
I've experimented a bit with some 189 and 190's but I don't find the accuracy I want w/ the 9 twist. I'd be interested to know what your charge is also.
Nice work on the rifle.