I recently switched from grease to Machine Gunner's Lube....it operates -50 to 650F.
What happens at 651°?
Till something better comes along......
TW25B Mil Comm Grease
Nope: According to the Mfg, TW25B quits at 450f.
"BOTH low temperature dependability AND high temperature performance
-85° F to +450° F (-65° C to +232° C)"