I got corrected on The Firing Line forum a month or two back on the difference between throw-away and throw-down. Two other terms ought also be included: Saturday night special, and Junker. And another class that doesn't really have a commonly used term for them.
First term: THROWDOWN. Police vernacular from prewar days - a gun generally taken off a drunk or kid that was small enough to stash for a time when a suspect was shot during a "furtive" movement but later was discovered to not have a weapon. Then the "throwdown" could be used to justify the bad shooting.
Second term: SATURDAY NIGHT SPECIAL. Racist term also of prewar usage from the phrase "niggertown saturday night". Implying that it was of the type used in colored bar fights or shootings. Today's equivalent is the underground police jargon "NHI" for "no humans involved" regardless of ethnicity.
Third and Fourth terms: JUNKER and THROWAWAY. The phrase "hotter than a two dollar pistol" applies here. Shoddily made clunker likely to fail to fire or blow apart if it did go off.
There was actually another class of pistol here that were represented by Iver Johnson and Harrington and Richardson revolvers and others into the sixties. Inexpensive but a good value for the price. Good guns for the money, but when neglected or misused could become junkers.
Relatively recent ( last two decades ) research has shown pretty conclusively that most post civil war gun control measures were initially "Jim Crow" laws and not intended to apply to other than blacks, hispanics, or other ethnic minorities ( foreigners ). Someone else can fill in the citations.
Sad story to tell, and not one told in the sixties when I was growing up in California. Rock and Roll, Haight-Ashbury, the anti-war movement, and Timothy Leary and psychedelics were foremost in my generation's conciousness at the time.
edit note: I see others posted between the last time I looked and the time I got my post up. Slow typing.