How hot does a hit glue gun get before it melts the glue stick?

Around 385 f? I'm not sure

Glue guns come in low temperatures and high temperatures (hot melt) versions. low temperatures glue guns come in at approximately 120° C (248° F) and are all suited when high temperatures are undesirable, such as gluing cloth and lace.

these temps are for the art/craft type glue guns though not for the industrial ones you might get at a hardware store:

high temps guns = 385° f

low temps ones = 250° f

And this just in cause of interest:

low temp glue guns are recommended for use of polystyrene foams glue from high temp guns will eat into the foam though it doesn't burn it so it's recommend to let the hotter glue from a high temp guns cool down for a second or so before contacting the actual foam can even extruded it onto something else like popsicle stick or something to allow it to cool

I think that high temp guns can be extruded onto rubber though like inflated balloons