Looking at the hammer plungers on both assemblies, BOTH have WINGS. One has very large "wings" and unlike any I have seen. These wings are so large that they contact the housing when the hammer is down. While contacting the housing, the tension is taken off the hammer and therefore the hammer is loose. I realize the housing with the "loose" hammer is not the one that is not allowing the bolt to open, but this hammer plunger doesn't look like it will even hit the firing pin. Where did you get these trigger groups?