Installing new double din aftermarket radio question

I?m installing a new pioneer double din radio in my 2003 avalanche. It?s all wired up and working.  The problem that I?m having is after installing the brackets on the sides it won?t fit all the way in to mount it. Is it common to have to cut something out in the back to get the radio to fit in?

I did  when I installed an after market in my 06. it's a support bracket  for the stock radio. I also removed my ac controls so I could get my hand back behind the radio to help guide the wires.