Grease groove bullets at or just slightly larger than groove diameter, have the lube grooves to soak up the finning caused by the lands. Over sized paper patch bullets have no where to displace the swaging into the groove except of finning on the base, which is a big problem if the diameter of the bullet starts exceeding the bore diameter.
A minor amount of finning on the base won't bother much, longer finning and cupping of the base causes a lot of mysterious poi and excessive group sizes when you shoot at distance.
Then the bullet length to twist thing starts throwing it's chips on the table, and things can go horribly wrong at the target.