You did not say who made your Mauser.
The original sighting of these rifles was a very precisely measured bit of work.
Richard D. Laws, in his book "Backbone of the Wehrmacht" (1993) notes that according to original Mauser Obendorf documents, The K98k front sights were allowed to be shifted only .2mm either way off center in order to meet specifications. The sights were originally set up with quite precise gauges and jigs.
Your rifle is now quite far beyond this .2mm standard of acceptablity, of course.
It is quite possible that the sights have been knocked out of kilter and repaired in some less than ideal fashion, in which case, rotating them can hardly do any harm. But without the proper equipment, you will probably wind up with a cant that will affect accuracy, especially at long range. You should realize this.
A worse possibility, which I cannot rule out, is that your barrel is bent. Someone in the past might have used it as a crow bar. I am not sure how bent a barrel that would throw off a round to your reported sight setting would be, but I would not ignore this possibility. I have heard of it before.
I do assume that you know that the front sight must move in the opposite direction that you want the bullet to impact. I think that your post implies that you have shot and shifted the sight in steps at the range, that you know from careful, supported shooting that the groups were actually moving in a progression of consistent steps in the direction that you wanted. This is a problem for some.