Let me clarify. My first post was not clear.
I have a 16" threaded CAI RAS47.
The Muzzle Brake Retaing Pin (MBDP) is stuck. (Pictured, with slant brake unscrewed a little to show the condition.)
I tried PB Blaster, lightly tapping the sides MBRP, & a polymer hammer to loosen it up/get it free. That did not work.
The next option is to punch out The 1 pin that crosses/retains the MBRP. In the front sight block. I'm not going to remove the sight block, just 1 of the 2 pins.
Before I attemp this, & I have done it before, I wanted to know more about the copper substance on the pin (also pictured).