Jim, in theory,  the ocular lense (reticle) focus, should be independant from paralax, which focuses the target image ON the SAME plane as the reticle. However, as with human eyes, lenses may be cursed with astigmatism, or, they can be skewed (out of plane/not perpendicular to the axis) and/or off axis enough to cause distortion . . strange things can happen.

Assuming that, once you get close, you are attempting to achieve  paralax focus by alternately screwing the objective lense in/out (back and forth to 'fine tune'), THAT may well be a BIG part of your 'problem'. The lense cell is likely 'floating' in the screw lag, thus, once you get it close, fine 'adjustments' actually accomplish nothing - the objective bell moves, but the lense cell remains stationary. The 'cure' is to ALWAYS attain paralax focus from ONE direction; if you go too far, note the point of 'no return'; return the objective bell to the original  STOP and approach the 'mark' from a single direction; this will assure that the lense cell is is being puhed in one direction [and is] always in contact with an abutment, as opposed to 'floating' in the limbo of lag. With the Burris scopes, beginning at the nearest yardage and working out to the desired yardage has always worked well for me. I have observed many people fighting this 'problem' with both the Burris and scopes with similar paralax adjustment (not locking) features. Of note, the Lyman All American serries of scopes had one of the best and most desirable paralax focusing systems ever offered. The Lyman system actually locked the lense cell between the abutments; 'pushing' the ocular toward the turrets/eye required tightening the lock ring.

When the reticle moves [across the target] WITH the eye, the paralax is adjusted for a more distant range; when the reticle moves across the target in the opposite direction of eye movement, the paralax is focused at too short a yardage.

Good luck and good shootin'. R.G.