Ketch's Weapons Arsenal
As a top agent for the British Men of Letters, Arthur Ketch was an experienced hunter for the organization, hunting and executing their behalf with impunity. This job required Ketch to be well-versed in weaponry, both standard and mystical. On assignments he would travel with a small weapons arsenal in a simple case.
Arthur Ketch can be seen packing a case of weapons in 12.02 Mamma Mia, as he prepares to head to the United States. In addition to the guns, he also has an assortment of knives and other blades.
Heckler & Koch USP .45
Throughout the twelfth season, Ketch uses multiple guns. His main firearm appears to be the nickel-plated H&K USP .45 caliber. He is seen using it multiple times, including with a silencer.
Heckler & Koch USP .45 Expert
The gun Ketch uses during the firefight in the Men of Letters Bunker is slightly different than his nickel-plated USP. It appears to be an H&K USP .45 Expert.
When Ketch gets into a fist fight with Dean in 12.22 Who We Are, he pulls a small concealed gun on Dean after he begins to lose the fight. It appears to be a Walther PPK, the gun most famously used by James Bond.