Are you planning to install one yourself, or are you an existing setup?
If you find the trigger for a defensive firearm, you can install the included auxiliary spring to increase the pull weight by about 0.5–1 lb, making it more predictable.
You often need to squeeze the trigger while rotating the safety lever back into position during the initial install. alg-trigger-kp9
Pull weight often drops from a factory ~5 lbs to a crisp 2–2.5 lbs .
The most famous part of the story. Most KP-9 users must install the included roll pin into the trigger tail and file it down until the safety can just barely engage. Are you planning to install one yourself, or
It is widely considered the best upgrade for competitive shooting or rapid-fire "mag dumps" due to its hair-trigger nature. ⚠️ Known Plot Twists (Troubleshooting)
There has been historical debate about the harder ALG hammer "peening" (deforming) the rear of the bolt carrier over thousands of rounds, leading some users to polish or "profile" the hammer face to match the factory geometry. Pull weight often drops from a factory ~5
Once properly fitted, the ALG trigger transforms the KP-9's shooting dynamics: