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.
Trooper Mount carries with him a Remington 870 with an extended magazine tube when they arrive at the Blues Brother's concert to arrest them. Several other police officer and prison guards also uses them.
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...