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 ....