I bought a TC Hawken flintlock tonight at an estate sale. I pull the hammer back to full cock, pull the set trigger, then squeeze the front trigger, the hammer stops at the half cock position, and the flint does not strike the frizzen. But if I just ignore the set trigger and squeeze the front trigger at the full cock position, the hammer falls all the way forward, and the flint strikes the frizzen. Does anyone know what’s wrong? And how do I fix it? Thanks