The SIG-Sauer P226R is carried by Detective Sergeant Claire Wallace (Nora-Jane Noone) and Detective Garda Sean Prendergast (Aaron Monaghan), officers of the Garda Special Detective Unit (SDU) assigned to the Criminal Assets Bureau (CAB). A detective with the Belgian Federal Police is seen carrying one in S02E01. Daniel Katz (Kuno Bakker) uses one in S02E03. In a continuity error, a holstered P226 is seen carried by Inspector Vince Thijs (Gilles De Schryver) instead of his Glock 17 in S02E06.
Glock 17
The Glock 17 is carried by various members of the Belgian Federal Police, including Chief Inspector Christian De Jong (Wouter Hendrickx), Inspector Vince Thijs (Gilles De Schryver), Detective Mila Albert (Maya Albert) and Detective Mathis Blanchet (Arend Pinoy). Detective Garda Sean Prendergast (Aaron Monaghan) briefly carries one when in Belgium in S02E04.
A CZ P-07 is one of several firearms offered to Aubrey Cline (Bert Kettermans) by a Limerick weapons dealer in S02E03.
Submachine Guns
Heckler & Koch MP5
Variants of the Heckler & Koch MP5 are seen carried by Belgian Federal Police Directorate of Special Units (DSU) operatives throughout the series.
Shotguns
Mossberg 590
A Mossberg 590 is carried by a Belgian Federal Police DSU operative in S02E04 and S02E06.
Assault Rifles
M4A1
A variant of the M4A1 is carried by multiple DSU operators in S01E05.
Unknown
Rifles
Tikka T3
A scoped Tikka T3 is used by Aubrey Cline (Bert Kettermans) whilst working in Ireland in S02E03.
FN SCAR
A scoped FN SCAR 17S is used by Aubrey Cline (Bert Kettermans) in S02E05. A Belgian Federal Police DSU operator is briefly seen carrying a variant in S02E04 also.