I found this a bit heavy-handed, even preachy, but the critics love it.
Images Journal closes its review with this:
Gun Crazy is one of the great American movies, a giddily romantic story of two people who thrive off of each other and only completely come to life when in each other's presence. Some people might call Citizen Kane the great American movie. I might just opt for Gun Crazy instead.
Slant Magazine gives it 3 out of 4 stars and talks about Freud and phallic symbolism. FilmSite.org says, "the forerunner of director Arthur Penn's Bonnie and Clyde (1967), is considered by many to be the ultimate B-movie - with film noirish elements." DVD Talk says, "It's one of the most popular films noir because, like Kiss Me Deadly, it's just so much fun."
It's listed in the book 1,001 Movies You Must See Before You Die. TCM has information. Rotten Tomatoes has a critics score of 97%.