130 to 140gr bullets will work best in a 1-8twist barrel. I would look at the 130 Berger VLD, 130 JLK, 130 Norma HP, 140 Berger VLD, 140 JLK, 140 Berger BT, 140 Hornady A-max, and the 142 Sierra Matchking.
Pick any of those bullets, then use RL15, Varget, or H4350 in a Lapua case with a CCI or federal primer.
For 130gr bullets start around 38gr of H4350. That's the first combination I tried (130 JLK, H4350, CCI primer, Lapua case) and I'm getting consistent sub 1/3moa five shot groups at 300. And my rifle is not as fancy as yours! Wish I had a stolle f-class action *drool* make sure you post photos of those bughole groups!
