Is the flash hider on the SG553P put on with locktite, red or blue?

It's high-temp stuff. I've had to use MAPP gas to get mine off. Might want to try butane first but that maxes out around 550F. Let it cool down then try to give it a good "snap" with a wrench. Highly recommend getting an AAC style tool vs. using the flats.

Appreciate the advice, thanks.

Gunsmith locked it tight in vice, applied heat and it came off.