Not a suggestion specifically for long range, but shooting times is the most objective, technical oriented magazine i have found outside of the internet. less advertising than most, and good wighting. i look forward to mine each month.
this right here is as good as it gets... and it's free!
all the shooting magazines I've looked at always get into pistols and AR's more than LR rifles. I page through semi-auto short barreled personal defense weapons to get to the one article every so often on long range shooting. Everyone is afraid of the ethics thing and it just probably doesn't have the readers' interest as much as the more "fun" and exotic shooting sports.
Yes, Precision Shooting is an excellent magazine - Precision Shooting Magazine - Welcome While it doesn't state it, I believe they will sell you a back issue so you can get a feel for the pub prior to putting up the $37/year. AND, they have a LOT of relevant books for sale.
There is also an online pub from the UK - Target Shooter - Target Shooter
The Fifty Caliber Shooters Association (FCSA) also has a great, professionally done pub - but you need to become a member to get it (or pay a lot for back issues)...and, of course, it is focused towards folks shooting 50 BMG-type rifles. That noted, there is a lot of transfer for ERL shooters below 50 cal. They'll send you a current issue for a look-see ($2.95 for S&H) Fifty Caliber Shooters Association - read about half way down the home page (this link).
There is also a semi-pub that is one of the best you will find - AccurateShooter.com Bulletin - AccurateShooter.com Bulletin. Use the calendar on the right to browse back through their "product" - updated daily.