Muzzle Thread Protector

This screw-on sleeve is designed to protect the muzzle threads of certain firearm barrels when no muzzle device is installed. Its circumference is ribbed for grip so that it can be screwed on and off by hand. Supported thread specs are:1/2"-28, commonly used for .223 Remington and similar chamberings9/16"-24, commonly used for .40S&W, and sometimes for 6.5 GrendelI fitted this to a Grendel Incursion barrel by Alexander Arms.5/8"-24, commonly used for 6.5 Grendel/Creedmoor and for various .30-caliber chamberingsIt's not yet clear to me how this thread protector will handle the heat of the barrel under normal use, so this may very well be a pointless endeavor aside from the learning experience regarding thread specs and maximum temperatures.The threads were generated with Dan Kirshner's Threads library in OpenSCAD, using thread diameters oversized by 0.5 mm.