I've got a Daniel Defense 14.5" 5.56mm Lightweight Mid-Length Barrel with the low profile gas block that appears to have a barrel imperfection of some sort. The blemish is located on the exterior of the barrel, about 5 inches from the muzzle (see the closeup photo I took of it). I've had the barrel installed on my rifle for about two months but only now noticed this problem.

What I'm trying to figure out is 1. ) whether this is something from the manufacturer or perhaps damage from when my gunsmith pinned and welded my muzzle device, and 2.) what the nature of the blemish is (e.g., imperfection in the finish, or something more structural). For 1.), given the location of the blemish, I'd find it hard to believe that my gunsmith created it. Opinions?

(hash marks on measuring tape are millimeters)

Welder's ground to the barrel?

Looks like an arc blemish to me.  I would say it was likely caused by your smith.

It was your gunsmith.  From the weld. I don't think it's going to hurt anything.

Hey everyone, thanks for having a look at this. I've taken a better photograph with more direct lighting, and it would indeed look like a weld mark of some sort. What's still up in the air for me is whether this could be considered a safety issue. Certainly the finish has been melted away, so something would need to be done about that to head off any corrosion. I'll be following up with my gunsmith on this later this week.

http://hosted.brandonsilver.com/shared/blemish2.jpg

Personally I would get it replaced. I'm not one to freak out over a scratch on my gun but that is crazy. On a side note I don't see it causing any catastrophic failure seeing as pinned gas blocks cut further in the bbl then that.

that looks bad I would get it replaced op.

While I wouldn't like it .... I can't see it hurting anything other than your feelings. shoot it and enjoy.

While highly unlikely that spot is going to effect anything, your gunsmith is a hack and should be paying for a replacement.

Damage should've been disclosed prior to you receiving it as well as barrel replacement on their dime.

Yeah that's definitely from your smith. I would not fire that barrel. When I zoom in all the way on the first pic it looks like the hole might go all the way through the bore wall. Super unsafe. Would be making smith buy me a new barrel