In Season 1 (adapted from the first Reacher novel "Killing Floor"), Reacher travels to the town of Margrave, Georgia, and finds himself arrested for a murder that he didn't commit and is possibly part of a larger conspiracy. The entire 8 episode first season was released on Amazon Prime on February 4, 2022.
The following weapons were used in Season 1 of the television series Reacher:
In "Spoonful" (S1E03), Officer Roscoe Conklin (Willa Fitzgerald) takes a chrome Desert Eagle Mark XIX from a gun case and gives the pistol to Reacher upon his request for a gun. Reacher then uses the pistol as his sidearm for much of the season. The pistol is also seen in the hands of Mayor Teale (Bruce McGill) in the Season 1 finale "Pie" (S1E08).
Glock 17
Glock 17s are used by multiple gunmen, notably by a gunman threatening Reacher in "First Dance" (S1E02) (Reacher specifically refers to the pistol as a "Glock 17" in a later scene), along with hitmen in "Spoonful" (S1E03) and "In a Tree" (S1E04). Reacher himself makes use of a Glock 17 in "Pie" (S1E08).
Glock 26
Chief Detective Oscar Finlay (Malcolm Goodwin) carries what appears to be a Glock 26 pistol as his sidearm.
M1911-Style Pistol
A gunman uses a suppressed M1911-style pistol to commit a murder in "Welcome to Margrave" (S1E01). Reacher describes the ammunition fired from this pistol as "nine-millimeter, 95 grain". As M1911 pistols chambered in 9x19mm do exist, this is not impossible. Another M1911-style pistol is used by "KJ" Kliner (Chris Webster) in the Season 1 finale "Pie" (S1E08).
Smith & Wesson 5946
The Smith & Wesson 5946 appears to be the standard sidearm of the Margrave Police Department. Officer Roscoe Conklin (Willa Fitzgerald) is also seen using the pistol in "First Dance" (S1E02). Reacher (Alan Ritchson) also handles Roscoe's pistol during the same episode.
SIG-Sauer P232
What appears to be a stainless finish SIG-Sauer P232 is given to Charlene Hubble (Kristin Kreuk) by Special Agent Picard (Martin Roach) for protection in "In a Tree" (S1E04).
Revolvers
Smith & Wesson Model 60
What appears to be a Smith & Wesson Model 60 revolver with wooden grips is used by a gunman in "Reacher Said Nothing" (S1E07). Chief Detective Oscar Finlay (Malcolm Goodwin) uses one to shoot out tires later in the episode, although beforehand he refers to it as a ".32 snub nose".
Shotguns
Remington 870
A Remington 870 shotgun is seen used by Officer Baker of the Margrave Police Department in "Welcome to Margrave" (S1E01).
Attendees at an Axis Financial party are seen using Over and Under Shotguns to shoot skeet in "Spoonful" (S1E03).
Rifles
M4A1
During a flashback to his time as Military Police in Iraq, Reacher is carrying an M4A1 carbine in the episode "In a Tree" (S1E04). "KJ" Kliner (Chris Webster) uses an M4 while searching for Reacher in the Season 1 finale "Pie" (S1E08).
AKMS
The AKMS appears to be used by three Iraqi men Reacher kills during the same flashback in "In a Tree" (S1E04).
Other
Gun Locker Weapons
In the Season 1 finale "Pie" (S1E08), Reacher and Finlay are seen going to a gun locker where several shotguns and pistols are visible.