You are talking in the case of that 10-22 of the equivalent of using a 22 to hammer into a hole too small for it to fit, thus the pressure had no where to go. Chamber pressure is mainly against the walls of the chamber as long as there's not a restriction in the bore to stop the bullet, it's going to go the path of least resistence. There is no way that the small bite that the rifling exerts on the jacketed or lead bullet would be enough to overcome several inches of 15000 lb epoxy. The one thing I'd be leery of would be temperature sensitivity as even thermoset plastics will weaken as heat increases, so if you are shooting a great many bullets in single settings, it'd probably be smart not to go this route. I suppose there may be a way to do this with a solder joint at the end where you weep silver solder in also. This would be higher temperature, but it'd be a lot harder to get everything to flow evenly.