I was thinking that the target paper would have more of a bearing on being able to see holes at 300 yards than the magnification itself would. For example, if you shoot at a plain white piece of paper at 300 yards with a single black dot to aim at, .30 caliber holes will be fairly easy to spot, provided you don't hit the black spot exactly. On the same token, targets that have a lot of black, it will be very difficult to see a .30 caliber hole, no matter the magnification, especially if you hit in the black anywhere.