Just some suggestions on working loads.
Do all shooting off Sand Bags front & rear. Eliminate human error. And I have heard it all before, I
am good & I am solid & I don't move & yadda yadda yadda. B S. I have proved it over & over again outshooting others with their own rifles ON sand bags.
Use the Sand bags.
A Steel or Concrete bench is the best.
Shoot small of Bullseye you can see. Actually you do not want to hit the bull, it distorts the sight picture. You can move sights later. I usually tap my sight right or left of the bull.
Shoot 3 shots & change the target. Only 3. You can plainly see 3. Write ALL the details on the target.
Go up 5 grains & repeat. Then again & repeat, Then again & repeat.
Shoot 4-5 dif loads & then compare the groups.
Now change Patch material or lubes or both. Do everything all over.
Rarely, but once in a while you hit the magic combo soon. Sometimes it take s me 3-4 shooting sessions.
When you pick the BEST load, now do it all over & start below a grain & go up 1/2 grain under that load & increase up 1/10 th of a grain to the load & past til 1/2 grain past it. til you find The Load.
But there is a magic load for every barrel, I believe.
I start at 25 yrds. If it is not one hole group of 3 at 25 yrds, it is not even considered & I go on.
If you are in a hurry, don't even go, you are just wasting your time & supplies.
Your mileage may vary.
Now one guy told me "Hey, that is just too much shooting". I said OK, don't do it. I prefer 1"
groups. Others are happy to hit a 8" pie pan at 50 yards. It IS up to you.