pretty tight, take a hammer and invert it in your hand so you can tap the prop blades with the wooden handle. The idea is to set up a harmonic effect. Keep tapping the blades and applying as much tension on the puller as you can without bending something. Try to get the harmonic effect going and keep it going until the prop "pops" off. This method has never failed me. Back the nut off a 1/16 to 1/4 of an inch away from the prop but maintain enough threads so the prop won't fall off the shaft when it breaks loose. With the taper on the shaft you only need the prop to move slightly and it will be free. Good luck.