My son and I are just getting started in pb and picked up some Azodin Kaos markers. We come from a rifle/gun shooting background, with a passion for tinkering/improving firearms, so the Kaos triggers just NEEDED improvement.
First step was to install "over-travel" stops.
Reducing overtravel
I put painters tape on the trigger, pulled the trigger back and marked the point where the trigger met the marker frame. I disassembled the marker and removed the trigger blade, drilled and tapped a hole for #6 x 32 allen head screw. I then re-assembled the marker. I left the screw hanging out long, cocked the marker, pulled the trigger and gradually screwed the allen screw in a little at a time until the marker "fired". I re-cocked and re-fired several times until I got 100% function. I then added blue Lock-tite to hold the screw in that position.
The next step was more complicated and time consuming, but still worthwhile IMO. I added a forward travel stop screw (the very short allen head screw at the top of the trigger blade).
Reducing pre-travel
The trigger blade only contacts the frame at a very thin point, limiting the possible installation point for the screw and causing the screw to potentially interfere with the sear/dis-connector. The point of contact was fairly easy to see because there was a thin line of paint missing from the trigger blade where it made contact with the frame.
I removed the trigger blade, and removed the dis-connector and spring, drilled and tapped a hole for another #6 x 32 allen-head screw. I had to file the screw down using a Dremel to shorten the screw to avoid interfering with the dis-connector. I took a guess at how long it needed to stick out the front of the trigger, re-assembled everything, cocked the marker, "fired" the marker while holding back on the trigger, re-cocked the marker and slowly let the trigger forward....but it did not re-set the trigger. I had to disassemble the marker and shorten the screw a bit more, then re-assemble and re-do the firing process until I got the length just right. You know it is good if you can: cock the marker, fire it and hold back on the trigger, re-cock the marker and slowly let the trigger forward; before the trigger stops moving forward you should hear a distinct "click" sound, which is the trigger re-setting. If you don't hear that, the screw needs to be shortened more. Mine only protrudes about 1/16" or 3/32" from the front of the trigger blade.
Adding these two screws really shortened the trigger pull to remove any "extra" travel.
The next step is only recommended for folks with trigger working experience...you can ruin the sear if not careful.
"Stoning the Sear
Next, I removed the sear from the marker and noted from scratch marks that there was a good 1/8" to 3/16" of contact between the sear and dis-connector. I used a metal file to remove maybe 1/32" or 1/16" from the tip of the sear, and re-assembled to check function. It worked like a champ to further shorten the required trigger pull. I let out the "pre-travel" screw a bit to check for function and all was good. SO, I filed off a bit more, maybe taking out HALF of the contact. Re-assembled, function checked, bump tested and all was good. I was able to let out a bit more on the pre-travel screw so the trigger pull is now pretty short.
OH, I also wanted to
reduce the wobble in the trigger blade. To do that I cleaned the trigger with carburetor cleaner and a few Q-tips. I dobbed Vaseline on the trigger pin, and put JB Weld inside the pin-hole on the trigger. I slid the pin in and added JB Weld as I pushed it in, since a good bit gets squeezed out. I used the 5-minute setup epoxy, and let it sit for about 30 minutes. After that I pulled the pin out and trimmed off the excess epoxy with my fingernail. Re-installed the trigger and MOST of the wobble is gone. When I first re-installed the trigger it was a bit tight and slow to re-set, but a drop of oil and about 10-15 firings cured that.
I would be happy to answer any questions about the process for anyone interested in doing the same.