Prior to the mid-1950s, with the exception of The American Rifleman, there was almost nothing published in the USA in the way of general circulation periodicals devoted primarily to guns. Mainly some hunting/outdoors and men’s adventure magazines that might have an article or two regarding guns in each issue, such as Field and Stream, Argosy, etc. Not actually a periodical but an annual, Gun Digest started in 1944.
In the 50's and 60's my grandfather used to take the "big three" outdoor magazines. Field and Stream, Outdoor Life, and Sports Afield. When he finished them, he'd send them across the field to me, where I would read them over and over until they literally fell apart.
Then when I was in high school, I got a job through a class that took me downtown every day. I walked into a "People Drug Store" one day and saw my very first copy of "Guns and Ammo."
On the cover was a picture of a revolver under the legend...
"Smith and Wesson Model 19 "COMBAT MAGNUM"
I can close my eyes today, and still see it.
WOW! A magazine about nothing but GUNS? Who knew such a thing even existed? Then for years I poured over Guns and Ammo, Shooting Times, Guns, American Handgunner, Gun Digest, The Shooters Bible, and I don't know how many others. Skeeter Skelton, Elmer Keith, Jeff Cooper, Bill Jordon, Jack O'Connor, Warren Page, and others like them became my mentors. I never missed an issue for many years.
I've still got a number of those guys books today.