Are you adjusting with the arm up and a bullet seated?
If so, you are doing it incorrectly. Seat a bullet, lower ram, check OAL. If long (I typically start very long), the adjust the sweater down (WITHOUT a bullet in the seater). Reseat that round and check OAL again. Repeat until you get the correct OAL. Then do a few to make sure it is consistent. If crimping (sounds like you are), you will need to check OAL after the crimp as the OAL may change.
In the case of crimping, get close to the correct OAL (let's say within 0.002), then crimp and confirm the final OAL is where you want it. If still long, adjust seater, seat bullet, crimp and recheck OAL.