Hellboy II: The Golden ArmyHellboy II: The Golden Army - Internet Movie Firearms Database - Guns in Movies, TV and Video GamesHellboy II: The Golden Army
Hellboy's (Ron Perlman) weapon of choice is the Samaritan, his massive hand cannon from the first film. He is seen using it multiple times to take out various creatures.
Big Baby
When Prince Nuada (Luke Goss) releases the Tree Element into the streets, Hellboy goes and grabs "Big Baby", a surprisingly even bigger handcannon in his arsenal than the Samaritan to take it on. It appears to be a six shot that fires two rounds at a time. Before firing it, he winds up the music box in the back, apparently to please Big Baby.
Glock 22
Members of the BPRD including Liz Sherman (Selma Blair) and Abe Sapien (Doug Jones) use Glock 22 sidearms, which is determined based on the muzzle diameters. Since the BPRD is a department of the FBI, it makes sense for them to use the Model 22.
Glock 21
After Hellboy kills the Tree Element, police officers surround him and aim Glocks at him. Based on the muzzle diameter, they are likely Glock 21s in .45 ACP. They could also be Glock 20s in 10mm, but it is far less likely.