Does Tanderkross have a trouble question and answer area on their website? Have you checked to see if your MKIV is one of the guns that needs the safety recall performed on it or have you had it done already by Ruger?
Welcome to RT and your taking the time to use the introduction thread for new members would get you a good start into RT forum.
Thanks for the input. And yes, I have sent the pistol in to Ruger for the recall. I didn't install the Tandemkross trigger until I got it back. I installed one in my S&W Victory and have been very pleased with it. Called & emailed Tandemkross and cannot get a response. Customer service seems to be lacking a bit.