Trigger Slack

[Burninammo]

I installed a RPB 3 piece trigger group w/mag parts in my post polytech to make the pistol grip legal. There is a whole lot of slack in the new trigger. I don't know if "slack" is the correct term, but when I pull the trigger there is a whole lot of nothing and then the trigger engages. I reinstalled my Chinese trigger and the pull was fine but I started having double fires if I did not let off the trigger immediatly. (not good) So I had to reinstall the RPB trigger. Any suggestions on a trigger replacement or how to file this one to take the "slack" out of the pull. Thanks in advance.