One Chicago police officer is seen with a Colt Trooper in his holster during the Nazi Rally.
Walther PPK
When the Blues Brothers and their band go to Ray's Music Exchange, Ray (Ray Charles) draws a Walther PPK and fires at a kid who is about to steal a guitar.
M1 Flamethrower
Incorrectly referred to as the "M79 Flamethrower", Jake's Ex-fiance (Carrie Fisher) uses an M1 Flamethrower to try to kill Jake and Elwood when they are in a phonebooth.
Used by State Troopers, Sheriff's Deputies, Prison Guards and Police.
M16 (Colt SP1)
Jake's Ex-fiance (Carrie Fisher) uses an M16 when trying to kill Jake and Elwood after their concert. It has a birdcage flashider, but no foward assist, making it a Colt SP1. Also, while they are normally seen carrying original M16s, two US Army soldiers switch from M16s to SP1s in a continuity error when they are firing through a door when searching for the Blues Brothers.
Luger P08
The leader of the Illinois Nazi Party (Henry Gibson) uses a Luger P08 to shoot at the Blues Brothers during the car chase at the end.
Trivia
Weapons Guides
When she is at her beauty salon, Jake's Ex-fiance (Carrie Fisher) has two weapon manuals on her desk: "M79 Flame-Thrower" and "Anti-Personnel Mines". It's difficult to see the other text on the manuals, but from the logos, it looks like Government files. I wonder how she got those...