Terry- I have been working on the same and have developed a formula that seems to shoot very accurately in my Browning Xbolt. (22" barrel)
First, despite having a bullet depth measurement tool, I used the Barnes suggested OAL of 2.675". In any event, Barnes says to seat bullets at least .010 off of the lands, which is much more than people do for most other bullets, so I just went with their suggested length. On forums, users agree to seat them deeper than other bullets.
Next I started with a "mid" load of Varget; 37.0 gr. I read on some blogs that you need to drive these Barnes bullets hard, and .010+ from lands, so I skipped the lighter 36.0 gr charge of Varget which is phenomenally accurate with the Sierra 86gr HPBT (.25 MOA groups!). I have gotten a good feel for what different charges of Varget do. ~40 fps / grn difference.
After mixed results with the 37.0gr loads (some good 3 shot clusters but fliers .8" - 1" away), I bought another box of Barnes. Tried 20 @ 37 and 20 @ 38.0 gr (MAX LOAD). Ran tests yesterday, all 5 shot groups @ 100 yards.
Good news! All 38.0gr loads under 1" greatest dimention, .2 other axis.
Best group of the day: 3 rounds 1 sligtly enlarged hole, 1 round .2" above, 1 round .2 above that (my bad?). So a .6" x .1" group.
Velocities are also very consistent with Varget. 85gr TSX 38.0 Varget clocked out at 3130fps, 37.0 gr yeilds 3050. Many duplicate speeds were measured.
I am going hunting in the Condor Zone, and am glad that the highest powered charge is also the most accurate. I am told by a local guide there that the Barnes 85gr TSX WILL take down a wild pig. He said it WILL go through both shoulders (bones) and open up nicely but you should try to hit bones!
This load/gun is so much fun! Almost no kick, and commonly shoots 1", 3 shot groups at 300 yards (85gr Sierra Gameking HPBT 36.0 gr Varget). Now I will test the max Barnes loads at that distance. Other shooters at the range were yahooing at a 1 shot bullseye on a 1" target at 335 yrds up a at the top of a hill.
(also honed in on a good Barnes 130gr TSX in 270Win.)
Hope this helps.
Good luck and have fun!