I'm sorry but I just don't understand what you did in regard to the U channel. In the picture, I see what appears to be a long piece of aluminum laying in the forestock. Is this the U channel? Did you make it yourself? What's it made of? How did you make it? How did you epoxy it?
Or, is that aluminum already in the stock, and you just used your tool to cut out slots around it and underneath it to install epoxy or JB weld?
Thanks, Mannyrock