Yes, but is is WAY easier with added enzymes. Lots of threads on this forum from 2012 to say 2016. Some time after that things really started taking off with added enzymes. Many of us used step mashes to try to get conversion but you end up with low efficiency. The natural enzymes denature before you get gelatinization. Look up Andrew Lavery. He was one of the early pioneers for GF all grain and DIY malting.
IMHO, skip the pain relying on the enzymes in the grain and go straight for the added enzymes!
Edit: glutenfreehombrewing.com has posted some of Andrew Lavery's old articles: