Slow barrel, was getting about 2720 at 43.5 gr Varget (book MAX plus 2gr) with the Hornady 139 gr BTSP. For reference, this barrel when using 45.0 gr Varget (book MAX plus 1.3) is producing 2920 with the V-max and 2890 using 120 gr NBT, which seems an accurate charge (5/8-3/4")with both bullets, if that's helpful at all.
Hodgdon's data shows 43.5 as their max with the 139gr Hornady SP, and 45gr. with the Nosler 120 BT. Not sure what your source for data is, but if nothing else, it shows the disparity among manufacturers about what "max" is.
I'm going to try some Big Game for the 120 BT, as I found a keeper for the 139gr Hornady with 44grs. Varget. Seated .010 off the lands, 3 shots into one hole just over caliber wide by .540 tall edge to edge, cranking along at ~2950. Haven't been able to get much better than an inch with the 120's and Varget, and I'm not going to drop the speed below 3k by reducing the load below where I already have.
The Big Game looks to have good velocity promise, hopefully I can find the accuracy with it as well.
