So....
Banging the buttstock on the ground is better for the rifle than putting more pressure on the charging handle?
They are correct, though, to get the bolt to go back all the way forward, the buttstock on the ground pound will usually do it. Problem is, when I did this, I still couldn't get the bolt to retract and eject the case.
"Stomped" may be a bit of an exageration, I just needed more leverage. Nothing broke. Just set my foot on the charging handle and pushed down. Case ejected.
I saw a guy shear locking lugs off of an M16 bolt doing the "banging the stock on the ground" thing. Obviously, though, locking lugs aren't a problem on the FAL.
My solution to this issue was to leave my gas system set on "3". A lot of guys like it on 5.5 or so, just barely giving it enough pressure to cycle the given load. Reduces recoil, but this problem crops up then if you have a round that's generates less pressure than the rest.
The first time it happened, I was unable to pull the charging handle back with my hand. The second time, it was sticky, but I was able to retract the bolt by hand. After that, the gas system's been on "3". Problem hasn't come up since.