Done quite a few with marinetex.
It is an impressive epoxy when mixed precisely to instructions. Not so much so if you err a bit on the hardener proportions. Sensitive.
You can either use the powder scale to weigh out the proportions, or, mix all of both containers then toss out the surplus. Stir the crap out'ta the mix before using, you've got plenty of time to fiddle about 'afore she begins to cure. I often do two rifles with a full container then toss, its fast and reliable, if a bit wastefull.
If you invert the gun while waiting for the cure there will be few or no bubbles in the finished job.
Any places more than 2-3mm thick will show a bit of shrinkage after the cure. A second 'skim' coat may be required in critical spots like lug and tang, for perfect results.
I use Esquire neutral shoe polish buffed for release agent, and remove/replace the action screws at the 4-6 hour point, just to be sure.