If it's Rocksett, you need to try a hot water bath before you unscrew it. 10 - 15 minutes should do it. And it'd be good to know if it's got left-hand threads. I've never messed with a Galil, so I don't know that one.
Rocksett and Loctite are different things.
Loctite softens with heat.
Rocksett does NOT. You need to use hot water to loosen Rocksett.
they use rock set ( a high temperature loctite on them . add some heat and it's a right hand thread.
I am aware they are different. I just couldn't think of the name Rocksett when posting my comment, being lazy I used the word locktite. the water thing is new to me . do you stick it in boiling water?? and if so how long? the heat does work on rocksett . but it does require more than locktite.
Can only be removed by a hot water soak.