Convert Long Action 6br to 223

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.

The nut just takes up the space difference between the stem lengths on the SA and LA bolt heads, thus allowing you to use SA bolt heads on a LA bolt and receiver.

If you can find a 223-LA head that's the best way, the Extension Nut is the next best option, and then I have heard about people using precision washer to take up the space. Haven't tried the washer option yet myself so I can't speak for it.

There was a couple of LA 223 bolt heads for sale in the classifieds here, first time I've seen any up for grabs in a long time.