I wanted to see if I could get your help on switching my new rifle over. I recently picked up a long action flat back in 6br and want to change it to 223 for F/TR this summer. I'm going to keep all of the 6br components to one day switch back but would like to work with the 223 this year. I know I will need a barrel and long action bolt head that will fit but have also seen something about a firing pin extension nut. I just wanted to see if there was anything special with this extension nut or if there is anything else I will also need. Thanks in advance.