WHAT DOES COLT COMBAT UNIT RAIL GUN 45 MEAN?

I used to be pondering precisely the same detail.  Very low amp TIG welding may be the answer to simply welding the roll marks.  What is the perpose of copper?I believed that portion was intriguing contemplating I had listened to that the colt handguards ended up top quality.I have owned many M16's in every configuration and also the another thin