38 is probably plenty. With most calibers you need only 30 - 35 to shoot at 1,000 yards.When I dial up the 30 MOA, I still have another 8 that I can go up. That seems like a decent amount of room that is still left, but I don’t know if it really is or not???
Your problem is a failure to make your reticle point to the center or your bore, but you got closer with practice.
I mounted another scope today, and got it nearly perfect. I will always be able to dial up for any range I might want to shoot at with it and not have to worry about drift left or right, unless it is from wind or a canted rifle, of course.
I used to carry dope for each rifle/scope combination that had windage adjustments for the farther yardages. Not any more.
And like I said, I don't lap rings, bed scopes or worry about "stress" on my scope tubes, I just buy Burris Signature rings and get a perfect, stress-free fit every time.