https://www.adperk.com now has free one year subscriptions to Field and Stream, as well as Good Housekeeping, Ode, Popular Science, and Skiing (Alternative is no longer available)
You watch short videos (30 seconds to 2 minutes) to earn credits, which you redeem for magazine subscriptions. Usually takes only about 10-15 minutes to get the needed credits. The subscriptions do come, no credit card required, and no influx of spam.
Just a note: I did this for the Good Housekeeping Magazine and I got my first issue within 7 weeks.