Yall were very helpful on my first post and I hoping for some more assistance.

I have a DD MK18, and after installing a new fixed sight on the front, noticed the little lip on the muzzle break.  I have never had this happen before, and to be quite honest, I am nervous. This is one of my favorite rifles and I do not want to further damage it. I have approx 3k rounds through the upper, with almost all through the mb. Up until recently (I believe) this had not happened.

I figured my next step is to take it to a gunsmith, different than the one that installed the mb. But I dont know what to say or ask rather than... this looks like a bullet hit my muzzle break, help?

If something like this happens, does it usually mean something is damaged elsewhere in the gun? What should I ask/look for at the smith?

Thank you all. (Pictures Below)

https://imgur.com/a/CkxyqgL

Parts List:

* Daniel Defense Grip -

* 10.3 Daniel Defense Mk18 Upper -

* Spikes Tactical Honey Badger Lower -

* Surefire Muzzle Break and Warden -

* Eotech Exps 2-0 -

* Vortex Magnifier -

* Magpul BAD Lever -

* EPT MOE Lower Parts Kit -

* Daniel Defense BCG -

* Daniel Defense Fixed Front Post -

* Surefire Vampire Scout Light -

* Magpul Angled Foregrip -

* Daniel Defense Rail Covers -

* Troy BUIS Rear -

* B5 SOPMOD Enhanced Stock -

* Geissele Super 42 System -

* LMT Buffer Tube -

* CMC Trigger 3.5 -

First thing to check - is it tight still? Did it come loose?

If it's loose, tighten it.

If it's not loose:

What ammo were you shooting? Are we talking some nice Black Hills 77gr OTM that goes great with the 1:7 twist, or some gunshow reload 40gr v-max that shouldn't have ever made it into any self-respecting person's possession?

If your muzzle brake is tight and you're shooting good factory ammo, then take it to the gunsmith. Because either your muzzle device isn't on straight (loose), or your ammo isn't coming out of your barrel straight. If it's the latter and it's not caused by bad ammo, then you've got something wrong well beyond my understanding.

If I had to guess, I believe it happened same time as my batch of bad Frontier Hornady Ammo. See this thread - https://www.ar15.com/forums/ar-15/Punched-a-hole-through-primer-area-of-casing-casing-got-suck-to-bolt-face-/66-733254/

During that same range session I had a shot that was extremely 'sparky.' At the time I figured it was just the over-pressured round, but now I am wondering if that was the strike.

A question, and it is a question since I'm grabbing at straws here, but could a muzzle crown problem cause a bullet to deflect that quickly?