Looking for a little help regarding a problem with my CZ 550 lux ( .243 ) , I have had the rifle for about 4 years and never used the "set trigger " however recently I have tried to use it a couple of times , pushing the trigger forward to engage the set feature. Sometime it works and sometimes all I get is a "click " as if the hammer is dropping but the round does not go off , on inspection of the case it shows no strike on the primer. This only happens with the set trigger , I have not had any misfires using the normal trigger.

I have had it into a couple of local gunsmiths , each time they think that the issue is fixed but it comes back , because the problem is intermittent getting a resolve is proving impossible.