Theoretically yes, if the base is cut square in the mold, and its dimensions produce a bullet precisely fitted to its barrel. Ever since Dr. Mann's experiments over 100 years ago proved it so, it is gospel that the base of a bullet is far more important accuracy-wise than the point. An unskilled caster could induce flaws in the bases of bullets cast in a base-pour mold (poor fill-out, lumpy sprues, rounded corners, etc.) where the base of a nose pour bullet theoretically wouldn't have those defects, or at least the propensity for them. In practice though, there isn't much real world difference that I can see.
If I were to build a killer single shot target rifle to the tune of several thousand dollars, I would probably hedge my bets and have a custom nose pour mold lathe bored. Otherwise, accept the teeny tiny groups shot by the CBA wizards in benchrest competition mainly with base-pour molds as proof that it pays to be anal about a lot of other things rather than which end of the mold lead gets poured into.
