Originally Posted by Topshot
I...I put it down to barrel whip. I think it depends on where the end of the barrel is pointing on bullet exit as to where the bullets land. It may be a case of one bullet exiting at the top of the barrel flex and the other exiting at the bottom of the barrel flex.
That is exactley what I think it is. When working up loads in my rifle, I will often see a 2 - 3 inch difference in POI when using the same bullet and only a grin difference in load. The difference is usually vertical or almost verticle.
That small differnce in velocity would not account for the difference in "drop" and heavier bullets dont drop any quicker than light bullets. If you hold a 300 gr bullet side by side with a 100 gr bullet and drop them at the same time, both will hit the ground at the same time.
It's almost certinly barrel harmonics IMO