Off the track
I think we are going off the track here a little.
Personally, I would reload from the start. I would use 80gr bullet heads for roe and I would start with lapua brass. Even if the barrel needed a few bullets through it to wear it in, you are already finding out what your rifle requires.
IE, get a starting load and work up to the maximum using groups of 4 or 5 bullets, checking for pressure signs. This should be about 20 thou off the lands. (that is already 20 to 30 bullets run through the rifle)
Then make some more bullets up in groups of 4 or 5 and edge the bullet out in 3 to 5 thou increments until it is 5 thou of the lands.This will put another 20 to 30 bullets through the rifle. Check for pressure signs as you move the bullet out as pressure increases. You may have to move the bullet further from the lands to get more accuracy.
You should end up with a good group after the powder test, then the group will hopefully tighten with adjusting the depth of the bullet seating.
You should end with a rifle run in, with a bullet that suits at a cost of approx 2 boxes of average ammo.
The lapua brass is a little more expensive but definately worth it. Neck size from then on in to provide the longest life possible from them.