I will give it a try before using the gel. If the water trick works, I can shelve the gel for later use.
If Mike says he wouldn't use accraglass in this scenario then there is no outcome whatsoever in which I would resort to using it, he has too much experience building to ignore. Between dampening the stock to whisker it and then staining and finishing it the likelihood of those gaps not disappearing are unfathomable. Plus, other things to take into consideration are that you want a nice wood to metal fit but you don't want it so tight that the parts become difficult to take out. You'll end up taking the barrel out to stain your stock and the forend snaps in half or the lock out to clean and lubricate it and the inlet will blow out, stuff like that. Wood expands and contrasts over time and if the inlet is too tight it will create cracks in the stock around the too tight part. Plus your stock is probably just acclimatizing to its new environment which it will do once you take it to a new environment or the seasons change.
Things to consider once you do decide to accraglass something down the road, not this issue, is that if you don't use the release agent you will permanently glue all of your parts to the stock. Also, while it is a miracle product for some fixes, using it when better fixes are available or doing a bad glassing job will either make it look completely worse or cause you hours of headache trying to remove the bad job and re apply a fix.
You should probably post pictures of the gaps you are referring to as well. Two things people commonly do, and I am guilty of this, is either sugercoat the problem to try and fish for a solution while still saving a bit of their pride, or blowing something way out of proportion in their mind. I'm particularly guilty of this last one as you're always your own worst critic.
