What is trim length on fired brass before reloading ? thanks

It would depend on your chamber, but more than likely it will be the same as the parent case. Properly built Ackleys should be able to fire standard ammunition. So 2.233" is max & trim-to is 2.223".

thanks that is what I decided after some thought.

More than likely the cases will shorten when you fire form them and you will probably never need to trim them again.