The most commonly used weapon is a not a real gun at all, but a device called a "Tesla Gun" purportedly built by Nicola Tesla in the late 19th century. It fires a lightning bolt that stuns an attacker but does not kill him, also creating a short term memory loss of the incident in the victim.
Pistols
SIG-Sauer P226R
U.S. Secret Service Agents Pete Lattimer (Eddie McClintock) and Myka Bering (Joanne Kelly) carry SIG-Sauer P226R pistols as their sidearms after the pilot episode. Other U.S. Secret Service Agents are seen carrying the SIG-Sauer P226, including Agent Sam Martino (Gabriel Hogan) in hallucinations and flashbacks as Myka's deceased former partner.
This is the most seen firearm on the show. And inaccurate, the Secret Service issues P229 DAK models chambered in .357 SIG to all their personnel.
SIG-Sauer P228
First seen being used by several unnamed Secret Service Agents, after Myka loses her PPK/S, she calls for a weapon and is handed one by a fellow agent. Due to continuity errors, Pete and Myka's sidearms switch between these, and the newer (And more accurate) P229's.
SIG-Sauer P229
First seen as Pete loads it while getting ready for work, changes to, and back from a P228 throughout the pilot episode.
Walther PPK/S
U.S. Secret Service Agent Myka Bering (Joanne Kelly) carries a stainless PPK/S during the museum event in the pilot episode. During the episode Regrets; Warden Corinne Huggins (Maria Ricossa), while being under the effects of the artifact pulls a blued PPK/S and shoots an inmate helping Pete and Myka break down her office door. Myka picks it up, and moments later aims it at Pete when she too becomes affected.
Glock 17
A Glock 17 (A non-gun aka flashpaper gun) is wielded by Sheriff MacKenna (Cornell Womack) when he threatens to blow up the church in Season 1, Episode 3: Magnetism.
Old West style Revolvers
Seen used by one of Raymond St. James' (Philip Winchester) characters, and 3 bad guys in Beyond Our Control.
Good chance they're Single action Army's, however revolvers in general are not my forté. If you can ID the revolvers that would be greatly appreciated. --Crazycrankle 20:14, 21 July 2010 (UTC)
Makarov PM??
In the episode Vendetta, Todd appears to be carrying a Makarov PM which he draws on Claudia.
Rifles, Sub Machine Guns & Shotguns
Heckler & Koch UMP
A guard outside the Japanese embassy in Implosion can be seen holding a H&K UMP.
M4A1
A Secret Service Uniformed Division officer can be seen entering the Japanese embassy while carrying an M4.
M1 Garand
Seen carried by two actors playing WWII-era US Marines in Beyond Our Control.
M1A1 Thompson
Seen carried by one of Raymond St. James' characters in Beyond Our Control.
Double Barrel Exposed Hammers Shotgun
Was wielded by Leo (Zack Ward) when he confronts Pete and Myka after a news report says they're wanted for kidnapping.