Hubley and Mattel, two I remember very well. Hubley used roll caps. I remember that Mattel used the "high tech" Greenie stick M caps. What kid growing up in the 50's didn't have a cap gun.
This Nichols capgun website will bring back some memories.
Remco made a water cooled M1917A1 .30 caliber machine gun and a bazooka. They looked real enough to scare folks walking down the street
watching them from my bunker.