I picked up a 14" hunter barrel (nice barrel) 3 or so years ago and played with it for a bit. I was trying to use copper bullets and felt that i wasn't getting the velocities to ensure good terminal performance at 200 yards (most bullets are designed to function well at velocities above 1800 or 1900 fps, even the Nosler BT). It sits in a box on the shelf right now.

If I was going to play with it again, I would look at the Barnes 139gn LRX bullet figure out what the factory recommended minimal terminal velocity is. In my experience the LRX have lower terminal velocity requirements vs the TTSX or TSX but it may not be low enough to get the range I want with the heavier bullet.

EDIT, From Barnes- the 139gn 7mm LRX bullet (30295) needs about 1500fps for 2x diameter expansion.

I just ran some calculations. If I assume a MV of 200fps for the 139 gn (I was achieving ~2000-2100 in 30-30 with 150gn loads with another inch of barrel) I would have 1690fps at 200 yards. The 127gn 6.5mm Barnes LRX requires 1600fps to ensure expansion. I am not sure if the 1600 fps is the "2x" expansion velocity or the "2x" expansion plus 100fps buffer that they use to recommend for hunting.