I changed out the original hammer spring with a Wolff/Murray 31 lb. one. Looked easy on YouTube. I will NEVER do that again. That was a test of patience. All those pushups, 15% incline, and pull ups finally paid off
I ended up using a needle vice grip, a regular vice grip, screw driver, rubber mallet and a bench vice. It wasn't anything like on YouTube ones. Those must be loose Chinese trigger groups. The Yugo was anything but loose.
Everything was fine until I altered the sear. That improved the trigger creep and pull but increased the hammer strength on the firing pin. The last shot of the day popped a primer, and smoked the firing pin spring. I had been looking at the primers all along and could tell it was hitting harder because I kept some cases from before I made the sear alteration and was able to compare. On the fiftieth round of of the day (Golden Tiger) the primer smoked out. Anyway, I ended up getting a new sear, reduced power sear spring, and lighter hammer spring from Murray and now I'm just glad that is over. As a result, I ended up with a smoother trigger but really if it is not broke don't mess with it to begin with. BTW, I won't be offering this service even for free
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