I'll be in the market for a pre ban M4 upper soon and I'm leaning on getting a 14.5" upper and installing a vortex or phanton flash hider on it. Is it possible for me to permately install it myself with shop tools, or should I have a gunsmith install it. Can a little propane torch and some silver solder be a quick fix? I know some companies sell them already installed, but Bushmaster only has the new phanton without the pointed ends. I was thinking of buying a 14.5" M4 upper and phantom or vortex seperately and permanently installing it myself. Any suggestions would help. thanks Billy