Got my first AR (from DSI) a couple weeks ago, a DS-15 Lightning. I took it to the range last week for the first time and put 100 rounds of Fiocchi 223 through it without issue. I went back today to finish the box and put another 100 rounds through it, again without issue. Then I tried some Federal American Eagle 223 rounds and of the 40 rounds I loaded, probably 6 or 7 of them did this:
This was the Fiocchi ammo: https://i.imgur.com/DH9veJi.jpg
This was the Federal ammo: https://i.imgur.com/QnELC6Z.jpg
So my question is, is this due to the ammo? Something with the gun? Or is this common if the gun isn't cleaned after 200 rounds?
Thanks in advance, and sorry if this is a newbie issue.