Strange lines on 5.56 LC brass

I purchased a few hundred rounds of (supposably) once fired LC 5.56 brass a couple weeks ago. Turns out that about 1/3 of it had been reloaded, so while working up the stuff that wasn't once fired for coyote hunting, I ran across a few pieces like the one in the pic below. Any idea what caused the axial lines that run half way down the case? I don't plan on loading them, but just curious as to what caused the lines. it's an LC 09 without the nato cross.

Thank's Greg

HK fluted chambers will cause that. They are OK for reloading.

edited to ditto what alsask said

Now that was a fast answer, thanks guys!