Check your orings. Make sure they're all lubed well. You may want to replace them, just in case.
Check your frame to make sure it's securely attached to the gun. Sometimes the frame screws come loose which keeps the sear from catching the striker.
Check your sear. Make sure the edges aren't worn down. You should have a good sharp edge on it. If not, get out the sand paper and start sanding it.
You didn't say what gun or what upgrades you have on it. Does it have a reg? You may be starving your gun - chronograph and see how much speed you have. If it's low, turn up your reg.
Never argue with an idiot; they'll drag you down to their level and beat you with experience." ~ Anonymous