Went to the range today to finish sigting in the scope on my 8mm Mauser.Started out with a box of some surplus the gun store had(don't know the country of origin or age).After i finished that box(15rnds) I had it shooting around a 2" group about 1.5" high at 100yds. So I had two winchester soft points left from a couple years back I then proceeded to shoot and they hit a full 5 inches loer than where I was hitting before.So I then break into a box Sellior& Bellot and the first shot is low like the Winchester(maybe my bad) but the other two of the three are higher than the surplus stuff.So after alittle more tweaking on the scope I get it shooting back where I want.So that brings me to my question.Is it normal for there to be this much difference in ammo brands?Also I heard that domestic 8mm isn't loaded to its full potential could that explain the low hits of the Win. verses the other( surplus and S&B)?Thanks.