Merlinco....also try PB Blaster to get some lubrication in there and maybe dissolve some of the crud. Keep applying it and let it sit for several hours or longer to give it time to work. Keep working the bolt back and forth to break it free, turn it CCW, then CW etc etc. sometimes this breaks the corrosion loose. Use never seize or equivalent high temp thread lube when you put it back together (if you get it apart).