riaan87,
First of all, welcome to the 'fire.
The marks shown in your picture are evident on both lands and grooves. That tells me they were probably there before the rifling operation. Also, if you look closely, they are evenly spaced radial lines with a pitch, like a thread. That sounds to me like they were made during the drilling or reaming operations as the tool was fed into the bore.
I would have a really hard time taking home a rifle with a bore that looks like this. Everybody wants accurate rifles, including me, and choosing one with obvious defects in the bore just goes against my grain. It may shoot just fine, and I hope yours does, but I cannot bring myself to buy rifles with obvious defects.
