Huma, Your gun should work fine. To trouble shoot it, start with pan ignition. Just priming with FFFg powder, does the pan go off every time with a sharp flint? A sharp black English or Rich Pierce white Missouri should give you plenty of sparks. If you are using one of those cut agates, some work, but most don't. Next if you have flash in the pan consistently, what is the size of the touch hole. 1/16th or 5/64th's will give the best ignition. Your firestorm has a patent breach which needs good , and careful cleaning. The Firestorm was TC's attempt to have a flintlock work with the synthetic powders, and some of the powder makers came up with pellets with black powder in the center to help with ignition, as most of the synthetics ignite at around 650 degrees, where as the ignition point of REAL Black powder is around 450 degrees. If your frizzen doesn't make enough sparks to set off a pan of black almost all the time, then i would pack it up and send it back to TC with a note. It has a life time warranty, and they will fix it, and get it back in a timely matter. You need to work on your problem in steps to get a good working flintlock. A proper working flintlock is a joy. If you don't have good Black English flints, PM me and I will send you a few to try.
Bill