My nine twist model 12 really likes 50 to 55 grain Sierra BlitzKing, Nosler HPBT, Hornaday FBSP and V-Max, especially the 53 grain with a BC of .290. I use 8208XBR, 3031, TAC, N133, and am still working on ideal seating depth, but typically I aim for .025 off. One load that I use as a benchmark to compare any load being worked up is a cheap, off the shelf load by American Eagle in the 50g tipped. These seem to shoot very well out of my model BVSS. 25.7 g of 8208 or TAC pushing a 52 or 53g load at 3300 fps seems to be a "Goldie Locks" load for my gun. As always, your mileage may vary.