Gil,
As you said, there seems to be minimal sear engagement. It follows that something is interfering with it's travel. When I've encountered hair sets, it's always related to some foreign material under the trigger (actually under the trigger return spring) preventing it from moving fully forward so the sear leg can move the required amount. You haven't changed the trigger return spring, so I can't see how the pressure could have increased. Seems it has to be something interfering with the sear movement. Does the trigger move freely, especially forward, after firing?
