Has anyone on here had any trouble with the 180 Gr. Gamekings shedding their jackets?

I went on a hunt the otherday and I was useing my 300 Win. Mag loaded with the 180 gr. Sierra Gamekings. I put two rounds in a Oryx ( Shoulder Shot) and ended up haveing to use my 338 RUM to put the animal down with a third shot.

While capeing the animal I found the two 300 rounds in the vital area , but they were just the jackets.

I have never had any trouble with other bullets shedding their jackets before this.
I was just woundering if this was a common problem with the Gamekings, Or if this is a fluke with the box of bullets that I have?

Thanks for any info that you might be able to help me with.
hunter338