A "match" disconnector has been pre-smoothed. You can either buy a match disconnector or work on your existing part. Yes, it will make a slight difference in trigger pull weight but mostly it helps reduce the gritty feel.
The center finger of the "three-finger spring" mates with the ramp on the disconnector. The center finger is dual purpose; it controls trigger tension and it pushes the disconnector up. Any friction from the center finger and the ramp of the disconnector will show up as a gritty feel.
The center finger must provide enough tension to make the disconnector spring up. A rough surface on the disconnector's ramp would require more tension. More tension would increase trigger pull.
The flat surface on the back of the disconnector rides on the trigger bow. If it is rough, your trigger pull will feel gritty.
Here's what I do: Buff the mating surface of the center finger. Buff the ramp on the disconnector and the flat surface on the back. Also buff the trigger bow. I use a muslin buffing wheel with 500 grit compound and make the buffed areas look like chrome.
Next you must "tension" the center finger by partially reassembling the gun. Install the trigger, sear, disconnector, and hammer. Leave the slide, thumb safety and grip safety out and swing the hammer strut up and out of the way. Set the three-finger spring in position and slide the mainspring housing up to it's normal position. The center finger is adjusted properly when it contacts the ramp of the disconnector just enough to take any free travel out of the trigger. Too much tension will increase the trigger pull, too little tension will not push the disconnector up (could cause a full auto condition). You may have to take the spring out and re-tension it several times to get it just right. Test by pushing down on the top of the disconnector where it protrudes from the top of the frame (trigger forward). It should pop up. There should be no free travel in the trigger.
Form the left finger in about the same arc as the center finger. This is a good starting point for adjusting the sear tension.
