Sear and tumbler disengage problem

[Goo]

I am having some problems with the trigger dis-engaging the sear from the notches in the tumbler of the lock on my current build::
 Here are the particulars mold and gun shop colonial flint lock operated by a single pinned trigger with standard trigger plate.
  A) Trigger will release at 1/2 cock when the gun is oriented trigger side up towards the ceiling but hangs up on half cock when trigger is pointing down towards the floor.  B) The trigger pull seems really strong::
What I have done so far in an attempt to correct the problem is
#1 add some metal to the trigger where it contacts the sear to make sure it gets enough lift.
 #2 relieve the inletting above the sear to provide adequate clearance 
#3 clean the lock and check the fly to make sure it is free to move as intended
#4 remove a few thousandths off bottom end of sear spring where it's bumping up against pivot point of the sear. 

Thanks in advance for ideas and advice

[SingleMalt]

Before you add or remove metal, blacken the inside of the lock with candle soot and run it through a few cycles.  Maybe just a bit of wood is in the way.

[smylee grouch]

Yes, make sure every thing is operating freely and make sure the sear isn't touching in the bottom of the sear hole, this might prevent the sear from seating in the tumbler notches fully.

[flinchrocket]

Don't forget that when the sear arm goes up the nose has to go down. So, put some transfer color on the whole thing. If your lock operates fine when it's out of the stock it's rubbing somewhere when you tighten up the bolts, that's why you have such a hard  Triggerpull. Your pushing the sear into the wood.

[Goo]

Don't forget that when the sear arm goes up the nose has to go down. So, put some transfer color on the whole thing. If your lock operates fine when it's out of the stock it's rubbing somewhere when you tighten up the bolts, that's why you have such a hard  Triggerpull. Your pushing the sear into the wood.

Thanks that solved the problem