Green 648 press fit retaining compound is some wicked stuff. It's also fairly expensive, since it's usually in the larger bottles.
Not green 290 which is a wicking compound.
I use a lot of red 276 at work but you should use quality grade 8 fasteners or you will have to heat it for disassembly. Holds on my M1a scope mounts pretty good, where blue repeatedly shot loose.
