G17 ?

Yes, but I'll bet it's NOT a bur; nor, is it a genuine divot. (You write the strangest posts!)

Instead it's the, 'bearing line' that's caused by the barrel recoiling against the top of the slide opening. All Glock barrels show this line; the more you shoot the pistol, the more distinct the line will become.

It's NOT an issue; it affects nothing; and, you can forget about it.

Next problem ....

I,ll Take That As A Compliment.

About a week ago,I had my local gun-smith install Trijicon sights.When I cleaned,lubed the gun,I felt something snag my finger on the top of the barrel.I thought it was a burr.After further inspection,I noticed that something ran down into the slide where the nut to tighten the front sight is.I was not lock-tite.It,s ciear in color,and quite brittle,enough to scratch the flesh on my little finger.Epoxy like.I got it off the barrel and trying to get it off the slide where it ran around the barrel and the muzzel port.The stuff dose,nt come off very easy.CHILL G.21.45,I just spend a little to much time in the wilds.