Can a judge issue a search warrant for evidence and/or contraband for a residence that is out of county?

At least one court has held that a magistrate outside of his or her jurisdiction may issue a search warrant to search a location within the magistrate's jurisdiction. The case is Bitner v. State (Fort Worth 2004). In that case the magistrate signed the search warrant in Young County while she was traveling for a warrant to be executed in her own county. The court found that the search warrant was valid, finding that it didn't matter where the magistrate was when she signed the warrant because the warrant was for a location within her jurisdiction. Inferring from that opinion, it doesn't sound as if the magistrate could issue a warrant to search property outside the magistrate's jurisdiction, i.e., in another county.

Janette Ansolabehere

The answer to the question may also depend on what type of magistrate the judge is. Gilbert, 493 SW2d 783 (Tex. Crim. App. 1973), indicates that the jurisdiction of a justice of the peace is co-extensive with the county.
The Texarkana Court of Appeals, on the other hand, found a district court judge could issue a search warrant for a place outside the counties covered by his judicial district because it was a "state court" and governed by Article V, Section 8 of the Texas Constitution. See Green, 880 SW2d 198. One problem with the Texarkana court's reliance on Article V, Section 8, however, is that this provision does not appear to have anything to do with a district court's geographic jurisdiction-- the type of authority at issue here.
Look also to Code of Criminal Procedure Article 2.10 where it provides the duty of every magistrate to preserve the peace "within his jurisdiction." It may be the better practice to limit search warrants to places within the county.