In "The Winter Line" (S3E02), Maeve (Thandie Newton) is seen using what appears to be an anachronistic Beretta Model 70 pistol in a World War II-themed world.
What appears to be a Glock 17 pistol is used by Martin (Tommy Flanagan) in "The Mother of Exiles" (S3E04). A suppressed Glock is used by Caleb Nichols (Aaron Paul) in the same episode.
Walther P38
In "The Winter Line" (S3E02), what appears to be a Luger P08 is used by a German officer in a World War II-themed world.
Submachine Guns
MP40
The MP40 submachine gun is used by German forces in a World War II-themed world.
FN P90 TR
The Westworld QA security force continue to carry customized red and black FN P90 TRs as their weapon of choice in the series.
Rifles/Carbines
Karabiner 98k
The Karabiner 98k is used by the majority of German soldier in "The Winter Line" (S3E02).
FN SCAR-L
Several Delos PMCs are seen carrying black, short-barreled FN SCAR-L rifles.