M*CARBO Brotherhood

T/C Compass Trigger Kit Results

I just finished installing the M*CARBO trigger kit in my T/C Compass (6.5 Creedmoor) using the hunting spring option. It is advertised as a 2.5 lb trigger pull kit. The rifle was new in the Fall of 2018 and I had put a couple of hundred rounds down range through it. Before the trigger kit installation, the average trigger pull was 4 lb 6 oz (70 ounces), but there was significant variation, occasionally to almost 6 lb (+ 37%!).

I was curious about how much improvement would be objectively achieved with the trigger kit, so I ran an experiment after I completed installing the kit. Using a recently calibrated Wheeler digital trigger pull instrument I measured the trigger pull in 10 sets of 10 trials. Each set of 10 provided min, max and average values (presented in ounces) and all 10 were averaged to provide average min, max and average values for the 100 trials. Here are the results and my observations:

  • My kit clearly shipped with a 3 lb spring. The average trigger pull, over 100 trials, was 48.4 ounces.

  • The trigger consistency was significantly improved, with a range of +/- 11%. There were several outliers, and I suspect that if those were removed it is practically achieving +/- 5%.

  • The new trigger pull was 69% of the factory pull.

Here’s the graphed data:

While I was hoping to get to the 2.5 lb trigger pull advertised for this kit, the 3 lb actually achieved is still a significant improvement, as is the improved consistency. The road to our local range has been closed by snow, but I have no doubt that the improvement will translate into tighter groups. At this price point it is a super economical alternative to a drop in trigger.

This was a good project for a father-son afternoon or evening project. The M*CARBO web site has both video and printable instructions, which are clear and helpful. One note, there is an error in the printable instructions which has you reinstall the trigger hinge pin prematurely in step 11, instead of in step 18 where the trigger is actually installed.

If you were thinking about this kit for your Compass, go for it!


I have done 3 Mcarbo trigger kits so far. One on my S2K and 2 on Glock pistols. So far, all three of mine have come out lower than advertised. My S2K is less than 3 lbs and both Glocks are less than 4 lbs. My results may have turned out so good since i polished all the trigger internals while installing the kits. One more Glock to do, my wife’s G26.

10 pull average on my S2K

Average on Glock 27

Average on Glock 22