Hey guys, just bought my first pack of Zwickeys (No Mercy). I took one single head out, put it on my arrow , and gently snugged it down. Shot a few shots to confirm POI was the same as my field points, then attempted to unscrew it. The blades will spin as I unscrew, but the actual threads are not turning. Before I break this thing with vice grips, heat, or other tools, has anyone else had this happen? Is this a known issue with them? This is literally the first Zwickey I've ever taken out of the package... not a good first impression.