I like Shooting Times and Rifle Shooter. They had a really good specialty mag this past year on just long range rifles. They are the same company, so some of the articles overlap. The Rifle Shooter is only a Bi-Monthly, so I buy it at the store. Shooting Times is a monthly subscription. Guns and Ammo is a good one too, but they deal a lot with AR's and handguns.
It is not dedicated to shooting alone, but when I subscribed to the varmint hunter they had some of the best shooting articles I've read. If you are a math/tech geek they usually cater to you. I have a couple that went into great detail on gyroscopic stability.
I'm lucky to have a father-in-law who subscribes to both and then passes them along to me when he's done with them, so I don't subscribe myself.
IMO print media isn't as convenient or efficient as online.
This web site (LRH) and many others including 6mmbr.com also have excellent articles.
I found an online source recently that is a blog written by the match director for mid and long range shooting at Ben Avery shooting range here in AZ, German Salazar. The guy is an amazing rifleman and has shared some really good stuff on his blog. The Rifleman's Journal