I expect what was meant was glass bedding. We know it isn't really glass, either, but a form of 2-part epoxy.
I have personally used many epoxy's for bedding various calibres, including 5 minute (at the range) as well as 24 hour 2-ton epoxy and JB Weld, along with Brownell's Micro=-Bed and Acra Glass in thin and Acra Gel mixes. Also, Decon Plastic Steel in the original 50:50 mix and the newer 7:1 mix.
I really liked using JB Weld, 50:50 & Devcon 50:50.
All have worked.