well, I am an idiot.  I got frustrated in trying to remove and or find someone with an H press to pop off my Saiga front sight.  I want to thread the barrel and install a JTAC brake.  I decided to carefully cut if off with a Dremel.  Well the front sight collar is off, but I scored my barrel by a millimeter, all the way around.  How big of deal is this?  How much pressure does the 7.62 make at the muzzle?  Is this something I have to be worried about?  Obviously, I am not happy with myself.  I guess I could have the gap SLOWLY TIG welded until it is full, and then work on it with a file until it is flush.

Not a big deal at all. You drill the barrel deeper than a millimeter when you pin the components anyway. Don't worry about it.

Thanks.  Things really came into focus when I threaded the barrel.  It really was not a big deal.