I bedded a Hogue stock yesterday and just took the barreled action out of it about 30 minutes ago.
I used the Brownells Acraglas Gel.
I did drill a bunch of 3/16" holes at different angles into and through the plastic so the epoxy would be locked in place. I drilled holes at a angle just in front of the action screw through the plastic recoil lug and drilled holes completely through the plastic ribs under the barrel that are close to the action. So I ended up with at least 12 holes that the epoxy completely ran through. I also drilled 8 holes, 4 on each side at about 45 degree angles in the first two inches in front of the recoil lug.
The action and barrel came out pretty easy, I used the release agent that came with the Acraglas Gel.
With all of the holes drilled into and through the plastic I don't think the epoxy will come out or get loose.